Keystone Manufacturing Company

Keystone Manufacturing was a tool maker operating in Buffalo, New York. The company’s products included ratchets, ratchet drills, adjustable wrenches, and socket sets. One of their better-known products was the Westcott adjustable “S” wrench, originally produced by the Westcott Wrench Company but made by Keystone from 1901 onward.

More info at

• http://alloy-artifacts.org/keystone-manufacturing.html
• http://www.collectingkeystone.com/
• https://www.garagejournal.com/forum/threads/keystone-mfg-co-buffalo-n-y.381959/