bentleyboy,
I have nothing specific to add as we cannot "authenticate" the watch that you are looking at.
We have no lists of vintage Piaget serial numbers.
If it is a Piaget watch from the era, then "Lucky You" since they are not that common. I have only seen them in the Piaget Private Collection in Geneva.
Just make sure of the Swiss gold hallmarks and that the watch/bracelet is gold. In those days, Piaget did not make steel or titanium watches.
Check the movement is marked as PIAGET and the movement reference number. In those days, the manual wind version was 9P and automatic version was 12P.


Good luck and show us your goodies if you go ahead.
Regards,
MTF