If I'm reading the manual correctly, there is a couple of shafts under the camera, linked by some bevelled gears, that couple the cocking lever to the lens. The shafts are held in brackets screwed to the body with, what looks like, screws similar to yours. I'd certainly have a look around that area to see if there are any vacant holes. But it does look like a screw that might be used anywhere and it may have come from somewhere else on the camera and just ended up in the bottom.