. . . ref 5500, 14 kt gold-filled, that I just had serviced by my watchmaker for a friend. It was acquired by his brother in Japan sixty years ago, and now my pal's keepsake.

Any info resident experts can share? Here are movement . . .

. . . and inner case back images . . .

. . . taken prior to servicing.
The bracelet is reputedly original to the watch.
Art