Those are called Nikonos II ''strap-attechment levers'' - you can try Bob Wartekin's Southern Nikonos Service Center in Houston / Texas http://www.southern-nikonos.com/
The Nikonos II I sent you was a companion to another Nikonos I from the same person. Both had the same neck strap attachment levers removed, so they must have interfered with whatever rig they used underwater and both were removed.
I always used mine on a neck strap (you have to put your gear on in the right sequence). Keep in mind that if you're nearly on the bottom, on your stomach, you may drag the camera thru the sand or whatever.