Here is my Nikon body cap. There are two versions included.

 Version 1 is very simple and flat. It has a 90 deg overhang on the bayonet lip but it prints fine without support. This prints faster than v2.

Version 2 has an better grip, a notch for alignment, a mount type label, and a chamfered bayonet lip for supportless printing. V2 prints in 50min at .2res, 10% infill, 90mm/s

They both fit well and don't touch the focus screw nor the mount lock pin. Some slicers will leave an internal spur (hollow area) in the thin walls but that doesn't effect the fit. In the photo the shiny one is version 2 and was printed on Kapton with no raft. The white one is version 1 and had a raft. All are ABS, .2 res, no support.

I wanted to put a smiley face on the flat area so you'd see it when you look through the aperture window of a manual camera but the printer can't print that small, especially with overhang so it's up to you to draw it on ;)