So, my watchmaker is putting this watch through its final paces, but I managed to take some photos today of the movement and case.
The movement is indeed a 9A 17-jewel unadjusted movement. It looks like it has a circle date code, but I can't quite make it out. This would put the movement manufactured in 1925, I believe. The serial number is 61564, which makes it about right for 1925.
The caseback, however, is a mystery and I wonder if it's a replacement. It has no identification and only the number stamped on the inside case is "1839." My watchmaker said he counted about a dozen jewelers' marks, which tells me the watch was well cared for over many years. But I also noticed that the caseback appears to have been damaged and repaired (the exterior caseback is in perfect condition so maybe it's something else). I didn't notice it while photographing it, but it is evident in the image. If it is a replacement, it bothers me none since it has been part of the watch for many decades. Any thoughts?
The watchmaker also said the dial does not appear to be refinished, although he was not 100 percent sure.
