Smith & Wesson First Model American Revolver with S&W and Springfield Research Service letters. Both letters identify the revolver as an S&W First Model American and state that it was delivered to the Springfield Armory in March 1871. The Ordnance Department purchased 1000 First Model American revolvers from S&W in 1871; surviving examples are scarce and highly desirable. The revolver has the S&W commercial blue finish with casehardened hammer and barrel latch. The two-piece walnut grips are oil finished. The barrel has a nickel-silver half-moon front sight and the frame has the oil hole in the bottom. The top of the barrel rib is roll-stamped: "+ SMITH & WESSON SPRINGFIELD MASS.U.S.A.PAT.JULY 10. 60. JAN. 17. FEB. 17. JULY 11. 65 &AUG. 24. 69 + " in a single line with maltese crosses at either end. "US" is stamped on the top of the barrel between the legend and the barrel latch. Small "A" Ordnance sub-inspection marks are stamped on the bottom of the frame behind the oil hole, on the left side of the frame above the trigger guard and on the left side of the barrel top strap. An Ordnance "P" proof mark is stamped on the right side of the barrel ahead of the hinge, in one cylinder flute and on the right side of the frame behind the recoil shield. The Ordnance Sub-Inspection mark which consists of the script initials "OWA" (Orville W. Ainsworth) in a rectangle is stamped on the lower left grip. The rear face of the cylinder and the underside of the cylinder latch are stamped with the assembly mark "L2". The serial number, "1137", is stamped on the butt.