I had read several years ago that alcohol and resin don't get along. I usually don't bother stripping bodies that I am going to repaint, I just prime them and go from there. In the case of the body that you have I might have lightly sanded the decals first. Resin Dude made a body like that and Big Donkey Resins has taken over the business. The Big Donkey site has not yet been updated to include the Resin Dude Bodies however, but I believe that they are available.
Let us know how you made out with the 3D printed body.