I got a case, dial and crown for this apparent Elgin Military timekeeper. Case diameter is about 30mm and it has a threaded stud and guide post in back. I had a 539 movement laying nearby but that doesn't match the dial feet so it must use a different movement. Has anyone seen this and know what it was used for?
Mike

back

crown

Hi Mike. Your parts are in fairly rough condition. They are from an 'instrument watch' which was used as an attachment to a camera during and after WW 2 to record time for things like aerial photographs and are mounted in such a way that the timer is photographed along with the image so the time shows up along the side of the image in the printed photo. The guide post on the back was to ***** proof the mounting to make sure it was correctly aligned so it would be correctly oriented in the photos that were taken.

If you want to try to put together some parts to make a frankenwatch from these you would need an Elgin Grade 685, 8/0 size, 18j, shockproof incabloc, hacking movement. These were made in true 24 hour and 12 hour varieties. Your dial is for a plain 12 hour movement. The true 24 hour variety goes 24 hours for one time around the dial. Both varieties have sweep second hands.

You also see these same 'instrument watches' made by Bulova since the U.S. military bought so many of them that they had to have two makers supplying them. As a result they are not particularly hard to find these days in good running condition.

Hi Jim,
Thanks for the info, especially what movement it should have. I didn't see it in the Military Timepieces book.
It actually looks a lot worse in the photos. I guess I should have cleaned it a bit first! Here it is a bit cleaner and exposed better.
Mike

Dial looks almost new.