Some Nikon cameras were inscribed to show they (once) belonged to the US government. Some are fakes, but very difficult to spot the difference from the
genuine ones.
I have seen Fs with US GOVT PROPERTY and U.S.GOVT.PROPERTY
Are both versions genuine?
It's not hard to add inscriptions on a camera. There was a completely working F DUMMY on eBay a few years back. Obviously a fake, but sold for a high
price nevertheless.


