Vintage Constellation

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FYI
The serial number is on the movement - like the calibre number that you can see
The numbers on the case back refer to the case style
Ask your watchmaker to take photos when you get it serviced
 
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Beautiful piece!

One thing to point out - it may have been water resistant/proof when new, but it probably isn't any longer. Your watchmaker can test when it's serviced, but most collectors try to avoid getting vintage watches wet.