The included factory letter lists this revolver in .45 caliber with blue finish and indicates it was one of 67 guns of this type in a shipment to Schuyler, Hartley & Graham on December 31, 1875. The barrel length and grips were not listed which the remarks note typically indicates the then standard 7 1/2 inch round barrel and walnut stocks. The revolver was engraved by the shop of New York based Master Engraver Louis D. Nimschke, one of the most renowned arms engravers of the era. The engraving features his distinctive scrollwork with beaded backgrounds, panels of crosshatching with dots, "Nimschke stars," gadrooning, fan patterns, and other details consistent with his known works. For example, in "The Colt Engraving Book Volume 1" by R. L. Wilson, serial number 114, serial number 23451 on page 334, and the three examples on page 340 all feature very similar engraving with some variation in the finer details. As is consistent across Nimschke's body of work, the engraving is beautifully executed and flows with the Single Action's contours and lines. The right side of the grip features a golden eagle with a rattlesnake in its beak and claws perched on a cactus based on the coat of arms of Mexico. This was a popular motif on Colt grips in the period suggesting many of these revolvers were destined for Mexico or the American Southwest. With the turmoil in Mexico in the second half of the 19th century and into the 20th century, the country was thirsty for American arms, and men of wealth and power often preferred a well-adorned Colt as their sidearm. In addition to the fine embellishments, the revolver features a blade front sight, "bull's-eye" ejector rod button, the one-line barrel address, the two-line patent marking on the left, assembly number "864" on the loading gate, and matching serial numbers visible on the cylinder, frame, trigger guard, and back strap. Provenance: The Nick Shannon Collection