There were no Nikon body caps on Thingiverse! So I made one for all to share!
Version 1 is very simple and flat. It has a 90 deg overhang on the bayonet lip but it prints fine.
Version 2 has an extended depth grip, a notch for alignment, a mount type label, and a chamfered bayonet lip for more precise printing.
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 ;)
I had success printing them in ABS at .2 res with no support. Raft is optional but without it the bottom edges are a bit sharp and your bed has to be PERFECTLY level.
Version 2 takes about 50 minutes to print with Makerware 2.4 raft.