Hi,
Congratulations on your purchase - any chance of a picture?. I'll try and find the part number but in the meantime have you tried Ed at Retroleds or Peter at Magical Digitals - they may have the part you need.
Edit - have a look at this website - they may have the part you need - try emailing them with the full watch details - http://www.ofrei.com/ClockPartsAndSupplies.html