Manufactured from 1958 to 1966, the Model 20 .38/44 Heavy Duty is a scarce variation of a Smith & Wesson revolver which are found in the S185000-S263000 serial number range. It is believed that fewer than 100 were manufactured. This example has the additional rarity of having a factory added Model 10 barrel. The included factory letter confirms the 4 inch Model 10 barrel, light lug and blue finish. It was shipped on 8 August 1960. A second factory letter further states, "There is no question that the Model 20 is extremely rare and that it probably was built on special request for Mr. Harris, as he specialized in these unusual variations, and it would not be unusual at that time for Smith & Wesson to manufacture just twelve samples for him." "Mr. Harris" references to H.H. Harris, a large Smith & Wesson dealer and owner of H.H. Harris Co. in Chicago, Illinois. The factory had to specially machine the Model 10 barrel to fit the Model 20 frame. The barrel features a serrated sight, "SMITH & WESSON" on the left side and caliber marking on the right side. The matching serial number is found on the butt, cylinder and barrel. The frame and crane have matching assembly numbers. The factory gold box is numbered to the gun and marked "LIGHT LUG" on the bottom. Includes papers and bore brush.