Total production of Model 1860 Army Richards conversion revolvers is estimated at approximately 9,000 in 1871-1878, and only a small number of the early production revolvers utilized 12-slot cylinders because the additional stops over the chambers proved to leave the walls too thin as can be seen on this example. The extra stops allow the revolver to be carried hammer down with the firing pin between two chambers. The revolver has matching serial numbers on the barrel, frame, trigger guard, back strap, and cylinder with "220" on the breech plate and loading gate. The revolver has a German silver blade front sight, the New York barrel address, an ejector fitted to the right side of the barrel, a notch rear sight on the recoil shield, "COLTS/PATENT" on the left side of the frame, and "44 CAL" on the rear of the trigger guard on the left. It is accompanied by some correspondence between collectors discussing the revolver, including a letter from Fred Sweeney noting that McDowell's Colt conversion book stated that only approximately two dozen of these revolvers are known today, and "I believe you would be hard pressed to ever fine a finer, more original specimen of this variation." He also notes that additional "220" assembly numbers can be found on "several internal parts except the barrel has #210."