This is an example of a documented much sought after Colt "Pinched Frame" Single Action Army revolver serial number 37. The Colt Factory letter that accompanies this revolver states that it was to the Colt's London Agency on January 5, 1874. The revolver is complete with a part-by-part eleven-page description by Ron Graham, co-author of "A STUDY OF THE COLT SINGLE ACTION ARMY REVOLVER". This revolver was purchased in the United Kingdom by the famous Colt Single Action collector Mel Torme in 1991. The revolver was described in detail in a October 1993 article in "GUN REPORT". In addition to the distinctive pinch-frame top strap found only on Single Action revolvers between serial number 1 and 163, the pistol has the true first style ejector housing without a barrel boss, first type loading gate, early hammer with extended bordered knurling on the spur, nickel-silver front sight blade and cylinder with small square stops with no approaches The revolver was originally chambered for the .450 Boxer cartridge but the Graham letters states that it was re-chambered by Colt for the .45 Colt cartridge in 1877. The top of the barrel is roll-stamped with the first style script legend "+ COLT'S PT. F. A. MFG. Co. HARTFORD. CT. U.S.A.+" with slanted crosses at either end of the marking. The two-line/two-date patent marking is stamped on the left side of the frame and "45 CAL" is stamped on the left shoulder of the trigger guard. London "CROWN/CP" and "CROWN/V" proof and inspection marks are stamped on the top of the barrel to the right of the legend and on the cylinder to the rear of each flute. The serial number "37" is stamped on the underside of the barrel, on the bottom of the frame, trigger guard and back strap and on the front face of the cylinder. There is no assembly number on the loading gate. The barrel, frame, cylinder, trigger guard and back strap have an English full blue finish. The hammer retains the color casehardened finish. The one-piece walnut grip has a high gloss varnish finish.