Given the very nature of vintage watches each is pretty much every one of a kind, attrition, modification, wear, the environment, everything thing assures that each of our older pieces is the only one like it. American pocket watches are even better in this respect because so many were sold as movements only to be cased by the jeweler in the customer's choice of metal and style, so many of these were one offs from the day they were sold.
So here's some of my rarities
Waltham model 92 CPR, this railroad grade watch was sold through Eaton's stores in Canada.
Illinois model 6 Bunn Special, 24j, if more is better lets throw more jewels at it.... part of a "horsepower" marketing war these things topped out at 26 jewels before sanity took over
1893 Waltham 14K pendant watch, this thing was basically NOS when I bought it... how the hell does something last over 100 years with barely a scratch? And yes, it gets worn.
Elgin combat diver's watch, only about 1200 of these were issued during the war with maybe another 2000 issued in the early fifties.
The survival rate is low at best, this is from 1944