I thought I still had it, but I can't find a copy. Paul?

One very interesting thing about these cameras is that they have the "signal" mechanism for double exposure prevention, which is widely reported to have appeared only after the war with the "Signal-Nettar" 518. To me it sort of looks like the 516 was supposed to be the natural successor to the 515, with perhaps some minor changes but mainly introducing the double-exposure lock, and then the war intervened before it had been produced in any numbers.

Mine has been a really stellar user camera over the last couple of years. It and a prewar 6x9 Wirgin are the two folders that I find myself using constantly.