Apparently Hamilton did not have signed crowns until the late 1950's. Those crowns had the stylized "H" raised on the end of the crown.
Hamilton started using the term "Masterpiece" in the 1950's as a marketing device. There was no model of watch that was actually named "Masterpiece".
Hamilton never made an automatic watch in the United States. They were all Swiss imports.
Towards the end of Hamiltons production, watches were sold through catalog showrooms [Service Merchandise] with Spiedel bands. So, these were original to the watches.
Hamilton never manufactured any of it's own cases. They used several different suppliers who always marked the inside of the cases with their company designation as well as "Hamilton". The case serial numbers cannot be used to date the watch. They were case manufacturer numbers, not Hamilton.
Unfortunately, there is little collector interest in ladies' watches. On the plus side, they represent one of the true bargains for purchasing a personal vintage watch. They regularly sell for less than half of what a comparable man's watch would sell for. Women are frequently wearing smaller men's versions--particularly the tanks. Reference