Reference Library
Keystone Watch Case Co. Case Trademark
![J Boss
Guaranteed
10 Years
[Keystone Logo] (Keystone Watch Case Co.)](/assets/images/media/Trademark-KeystoneWatchCaseCo-49.jpg)
Trademark Manufacturer:
Keystone Watch Case Co.Manufacturer Years Active:
1880 - 1956Trademark Markings:
J BossGuaranteed
10 Years
[Keystone Logo]
Trademark Issued:
November 13, 1900Traits:
Rolled Plate10 Yr. Rolled Plate