It's my understanding that, prior to 1963, Movado wristwatches had six-digit serial numbers, that started with the movement caliber number and then counted up sequentially from there; i.e., the first Cal.150-powered watch would be 150001, the one thousand and first 151001, etc. Yet, I notice that a 1940 Movado 6B/159 I have has a five-digit serial, while a 1942 6B/159 has a seven-digit number! Both have Cal.75 movements and stainless steel cases.
Here are photos of the inside of the casebacks:
1940 model, serial #82520:
![Image](http://i1131.photobucket.com/albums/m556/David_Askett/70BC1B9E-71F4-422E-B443-522855A8CA18_1.jpg)
1942 model, serial #0085520:
![Image](http://i1131.photobucket.com/albums/m556/David_Askett/8594E4E3-8E4D-4DB7-89EC-BBC7DE585AA9.jpg)
As if Movado's serial numbering system wasn't complicated enough, perhaps there were exceptions to the six-digit rule?
Any guidance would be appreciated!
Thanks,
Dave