A is hired by B to perform a task - Project X. They agree and sign contract which details payment terms, ownership, project scope, dispute resolution, etc. All goes well. Project is completed and payment made.
Three months later B returns and asks A for a separate project - Project Y. Both agree on pricing via email but no contract is signed. Project is completed, payment is made.
Six months later B returns to A for yet a different project - Project Z. Both agree on pricing via email but no contract is actually signed.
A dispute arises over ownership of Project Z.
Are the (more general) terms on the original contract still assumed to be accurate for this third project?
In other words, are there cases where a previously singed contract would be seen as an agreement for future collaborations?
I understand (perhaps incorrectly) that by default, leases tend to have the terms seen as extended if no new lease is signed but occupancy continues, but does this apply to other contracts?