It's U.S., and an amazing movement, probably the best wristwatch made in the U.S., on par with the best Swiss of the time (mid 50s). No JB Weld on this one please!
I use the same size tweezers for handling wristwatch and pocket watch parts; 1AM brass. No.2 steel are also good for handling almost anything, as long as you are gentle. No.5 steel for tweaking hairsprings etc. but not for picking things up.
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