I created a replacement UMD case for a broken PSP game. We're pushing the limits of a 0.4mm nozzle at this size but I got something reliable after 8 or so iterations. I would not consider this a permanent solution, but something that can help you get a broken game back up and working so it can be ripped or whatever. Otherwise it works just like the original. Assembly should be straight forward. Disc label goes against the part without the hole, and then gently snaps together.

*NOTE: I only have a PSP-3001 so I only modelled what was needed to make it work in my machine, There are extra features in the UMD case I left out that could be important for other PSPs. If you print this and come across such a case, I will make an update.