I am pretty sure that the last time the battery cover for my Nikon N2020 film SLR was seen was ~10 years ago. It has the optional MB-3 4xAA battery holder, which was kind of annoying to have to duct tape over to get the batteries to stay in place, and meant that I could not use the ΒΌ-20 mount screw once I applied duct tape. An evening with a calipers and I now have something that stays in place. If you need the set screw on the side, it's a M1.6, I believe.
Modeled in OnShape, as my first attempt at figuring out how to use surfacing primitives: https://cad.onshape.com/documents/222328d50b6ccc927e2ccb9c/w/2d02f8dfee33b1fd0849c574/e/92431bcc68b1cc2fa2b3dd24
Printed out of matte PLA, laid on its side; turned the temperature up a little bit for slightly better layer adhesion, at the price of slightly saggier bridges; used Bambu Tree Slim supports with 0.1mm top Z distance, and this seemed to make an easily-desupportable part with decent surface quality for everything except the downward-facing bridges on the back of the camera.
The author marked this model as their own original creation.