I downloaded a freely available .stl file that is a fan-made model of a space ship from a well-known sci-fi universe. The fan posted the file under a Creative Commons - Attribution - Non-Commercial license. I edited it significantly (by reshaping, deforming, resizing, adding details, etc.) and put it onto a stand I created. I 3D printed the resulting model and use it as a piece in a board game.
Two of my friends saw it: one wants to buy a printed copy from me and the other wants to buy a copy of the .stl file so that he can print it himself. Am I allowed to sell either of those things to my friends? One of my friends is telling me that since I've altered the work by more than 30%, it's mine and I can sell it.
If I do the same thing with a 3D file that has only a Creative Commons - Attribution or Creative Commons - Attribution - Share Alike license, could I then sell it?