Dear Jeff,
Thank you for your reply !
Yes, I thought the same, a so close serial number must be original.
The movement serial number is 503995, I will post some pics...
:
: I have not done an exhaustive study of the subject, but whenever I
: have checked, I believe that the serial number inside the back
: cover has matched the serial number between the lugs. Perhpas
: the slight mismatch in your watch occured during production or
: even during a servicing.

: Can you tell me the serial number on the movement? I have begun
: tracking these, and the patterns are interesting (and seem to
: provide information about the watches).

: Thanks so much for your message.

: Jeff

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