Thank you all for the additional insights and your friendly comments. SALMANPK, thank you for your guidance on the key pictures. For this shop I won't be able to take the watch apart although I should be able to get a movement picture in a few days so I'll work on that. I did attach the rest of the shop's pictures in case that helps.
For the serial number, it's my observation that people get sensitive about that, but what we're looking for is probably the first number after the A?



