The accompanying factory letter lists this revolver in .45 caliber and with a blue finish when shipped to B. Kittridge & Co. of Cincinnati, Ohio, on February 29, 1876. The barrel has the one-line Hartford address, the frame has the two-line, two patent dates marking on the left side, and the trigger guard is stamped "45 CAL" on the left side. The ejector rod has the bullseye head. Matching full or partial serial numbers appear on the frame, trigger guard, back strap, cylinder, and barrel. Per the included May 1974 dated letter of provenance, Dr. S.K. Spyridon acquired this SAA from friend and famed firearms collector William M. Locke in January 1966. As Dr. Spyridon states in the letter, "The single action was one of several guns that came out of a private collection in Springfield, Ohio, that Mr. Locke purchased. I, in turn, purchased most of these guns from Mr. Locke."