The short answer is that not many examples of this come to mind in the modern era in democratic, rule of law based legal systems. A full answer is a little complicated and I'm limiting my answer mostly to U.S. legal history.
Probably the closest example that is not from a despotic or lawless regime would be the post-WWII trials of participants in the governments of the countries that lost in World War II, especially Nazis, in the Nuremberg war crimes trials, when neither that venue, nor any codified set of war crimes recognized as binding by the offending states, existed at the time. These cases are on the boundary between criminal prosecutions in an ordinary legal system and a tactic of war outside the confines of strict legal principles.
While these cases involve violations of the ex post facto principle described above, however, they do not also involve a resentencing of an individual for an offense for which that individual was previously convicted.
Increases In Sentences Following Reconviction After An Original Conviction Or Sentence Is Vacated
In North Carolina v. Pearce, 395 U.S. 711 (1969), the U.S. Supreme Court held that when a conviction is overturned on appeal and someone is retried, that imposing a sentence higher than the one originally imposed is presumptively, but not conclusively, invalid.
This presumption was modified in the case of Alabama v. Smith, 490 U.S. 794 (1989), in which the U.S. Supreme Court held that this presumption does not apply in cases where a guilty plea is set aside in a collateral attack on a conviction, and the individual who previously pleaded guilty is then convicted following a trial.
A law review article from 1978 by Gregory P. Dunsky reviews the state of the law at that time, noting that many states categorically prohibit as a matter of state constitutional law or statute, the imposition of a higher sentence for a crime when the defendant is found guilty at trial, appeals the conviction and has it set aside, and then is retried on remand from the favorable appellate ruling, based upon Double Jeopardy analysis.
Multiple Sovereigns And Double Jeopardy In U.S. Law, More Generally
Certainly, the double jeopardy clause prohibits retrials of offenses for which a defendant is acquitted. And, generally speaking, this also limits appeals that have any impact on a defendant (some states like Colorado allow prosecution appeals even following acquittals in order to obtain a precedent with prospective application only that dose not affect the defendant in the actual case) by the prosecution of a final conviction.
Double jeopardy means that only one criminal trial on the merits of a particular crime is allowed in the absent of a mistrial (often due to a hung jury preventing either a conviction or an acquittal), a different sovereign (e.g. a prior foreign or state trial does not bar a federal trial for the same offense), or a reversal of a conviction sought by the defendant on appeal or in a collateral attack on the conviction.
For example, in Colorado, recently a policeman driving a rape victim home then raped her again and was given a 90 day jail sentence for that crime to which he pleaded guilty, and is barred from being retried for that offense in state court. But, the federal government then charged him for the same offense as a federal civil rights violation (to which he also has pleaded guilty, in part, because the key facts were admitted in his previous state guilty plea so the conviction would be almost automatic), for which he faces a much more lengthy sentence.
This is very closely analogous to the cases you cite, except that the federal civil rights crimes in question have been on the books since the 1800s, shortly after the U.S. Civil War. Thus, the exposure to federal criminal sentences for civil rights violations existed when the conduct charged was committed, rather than due to a new law passed after the crime was committed which increases the punishment for that crime.
In general, federal civil rights prosecutions are frequently used in this manner, and this does not violate the double jeopardy clause because the state government and the federal government are considered separate sovereigns.
But, as a matter of Department of Justice policy, but not U.S. Constitutional law or statutory requirements, the federal government refrains from retrying state prosecutions except in cases of grave miscarriages of justice, usually involving leniency or acquittals for serious civil rights violations in state courts.
The double jeopardy protections of the United States Constitution have always applied to the federal courts, and had parallel protections in state constitutions applicable to state courts, was later held to apply to state court criminal cases via the due process clause of the 14th Amendment via a doctrine known as "selective incorporation" on the the theory that double jeopardy protections were a necessary component of any judicial system that afforded due process.
Other Countries Double Jeopardy Rules Compared
Unlike the U.S., most legal systems in the world permit both convictions and acquittals to be appealed on direct appeal with the sentence possibly increased or decreased on appeal. In effect, in these systems, jeopardy does not attach until the initial trial and subsequent appeals and retrials ordered on appeal are complete. This protects against wrongful acquittals of guilty people and undue leniency in sentencing that can be harmful to the public by prematurely exposing people to criminals at large, and by encouraging crime when corrupt judicial systems protect the offeners, and not just excesses by prosecutors and courts at the trial level.
But, blatantly allowing a sentence that is final to be changed to be more harsh based upon a newly enacted law passed after the original conduct had taken place, is very uncommon.
Permitted Trials That Seem To Infringe On Double Jeopardy Concepts
There are also some situations that look like retrials with more harsh punishments which do not violate the double jeopardy clause under current U.S. federal law (state laws may vary).
Punishment based upon acquitted or uncharged conduct
One is that a federal court in making a sentencing decision is permitted to consider uncharged or acquitted conduct for the purposes of exercising its discretion in how to sentence someone for a crime for which they were convicted up to the maximum sentence allowed for the offense of conviction, if the judge finds that the conduct happened by the lower non-criminal standard of a preponderance of the evidence. United States v. Watts, 519 U.S. 148 (1997).
For example, if the allowed sentence for tax evasion is 20 years, but usually the judge would impose a 5 year tax evasion sentence in the absence of other evidence, but the judge receives testimony at sentencing that the defendant murdered someone in connection with his overall portfolio of criminal activities by a preponderance of the evidence, the court could sentence him to 20 years in prison on the tax evasion charge (even if the statute of limitations on the acquitted or uncharged conduct has run).
Another is that uncharged conduct for which a statute of limitations has run may be considered as a predicate offense in a RICO organized crime prosecution (which requires as one element, proof of multiple predicate offense that form a pattern of criminal activity by a criminal enterprise of which the defendant is a part), even if the existence of that predicate offense is necessary for the RICO conviction and the RICO conviction carries a much longer sentence than the underlying predicate offense did.
For example, musician R. Kelly is currently facing a RICO prosecution for a series of alleged serial cases of sexual abuses of minors among other things. In that prosecution, one of the predicate offenses is that he bribed a public official to get a fake ID for singer Aaliyah, who was a minor at the time, saying that she was age eighteen and thus old enough to consent to marry him, in 1994 (the marriage was later annulled), even though the offense was a misdemeanor for which the statute of limitations has long ago run and the alleged ultimate victim (Aaliyah) has been dead for many years. (Of course, the RICO statute itself was on the books in 1994 so it is also not truly an ex post facto prosecution.)
Ex Post Facto Limitations
The situation you are discussing, however, is really more of an ex post facto issue. The ex post facto clause (among other things) prohibits a criminal defendant from being punished more harshly than the laws in effect at the time that the conduct that is being punished took place. (As a footnote, the ex post facto clause is directly applicable to both the federal government and to the states under the original 1789 U.S. Constitution, even before the Bill of Rights was adopted in 1791, unlike the double jeopardy clause, which is part of the Bill of Rights.)
For example, some of the Guantanamo Bay terrorism defendants were tried in military tribunals for violating certain U.S. antiterrorism statutes enacted after the conduct that allegedly violated those statutes, and the appellate courts invalidated those convictions, despite government arguments that the offenses of conviction were common law crimes under international law at the time of the conduct charged (not because that argument was unsound in general, there are common law crimes under international law, but because the charges in question were not common law crimes under international law and only became crimes when Congress enacted the U.S. antiterrorism statutes under which they were charged).
International Variation In Ex Post Facto and Double Jeopardy Rules
The notion of a prohibition on ex post facto increases in punishments is much more broadly adopted that the double jeopardy prohibition with respect to which is a U.S. outlier compared to other countries in how strong this right is. The Soviet Union was definitely an outlier for allow that to happen.
France has a statutory right to have your sentence reduced any time that the sentence allowed for the offense for which you were convicted is reduced to below your sentence, as do many other European countries.
But, the U.S. does not. Ex post facto reductions in criminal sentences are allowed in the U.S., but they must either be authorized by the legislature or the result of an executive branch commutation of a sentence. A convicted criminal serving a sentence has no legal right in the U.S., in general, to benefit from a later reduction in the allowed sentence for their crime of conviction unless the original statute was unconstitutional (and not even always in that situation).
Controversial Applications Of Ex Post Facto Law Prohibitions
Also, note that while the legal principle prohibiting ex post facto criminal punishments is widely adopted, that doesn't mean that it isn't controversial as applied.
For example, one highly litigated issue related to ex post facto criminal litigation is whether SORNA (which imposed federal sex offender registration requirements) can be applied to people previously convicted of sex offenses.
Another area of controversy has been civil and criminal prosecutions of people who have sexually abused children for whom statutes of limitations have run.
A third has been civil rights violators who were treated leniently by segregationists court system or acquitted, who have not faced justice for acts that are now considered to have been serious crimes (e.g. lynchings).
A fourth circumstance involves the Guantanamo Bay terrorist prosecutions discussed above.