I recently acquired a 4992B with a 12-hour painted metal sweep second dial, SN 4C11245. The sweep second mechanism is intact. The Keystone base metal case appears correct, but has no military markings. Could this be a 4992B made for or converted to civilian use? Any help appreciated.
Thanks,
Dan Rom

Daniel,

I have a 4992-B Hamilton like the one you describe. I have always figured that it had been converted since it still has the military nomenclature on the back. This was done by changing the cannon pinion,hour wheel, and minute wheel with the same parts from a 992-B. Of course the dial had to be changed also.

I have also seen them changed as follows. Change fourth wheel from 992-B along with the cannon pinion, hour wheel, and minute wheel. Remove the sweep driving wheel and the center pinion along with the sweep pinion bridge. Put a regular 992-B dial on and it appears to be 992-B from outside. Of course the setting will still be by stem and not lever. You can also put it in a regular case since the sweep pinion bridge has been removed.

Hope this helps shed a little light on your question

Respectfully

Virgil

Anyone else have any experience with these?