Keystone Mfg. Co., 41-63 Chandler St., Buffalo, N.Y.
(* not to be confused with Keystone Drop Forge Co., Northumberland, PA. or Keystone Reamer & Tool Co., Millersburg, PA. *)
Manufacturers of the "Westcott" wrench
More information about Keystone at:
http://toolarchives.com/node/572...