This extraordinary U.S. Contract Colt Single Action Cavalry Model revolver was manufactured in 1878 and sub-inspected by Henry Nettleton (HN). The revolver is accompanied by a Gold Seal Letter of Authentication by Colt expert John A. Kopec. The Kopec letter states that this revolver is "totally correct in all respects" and speculates that it survived in "remarkable condition" because it was provided by the Ordnance Department to a state militia, never issued, returned to Springfield Armory following World War I and sold as surplus, distributed through the Director of Civilian Marksmanship, or held at Springfield Armory from 1878 until the 1920s and sold by the armory. The accompanying factory letter states the revolver was part of a 100 gun shipment to the U.S. Government Inspector at the Colt plant on July 30, 1878. The revolver has the Colt military blue finish on the barrel, ejector housing cylinder, trigger guard and back strap. The Colt "feathered" polishing marks are visible on the barrel on either side of the front sight blade and above the ejector housing stud. The frame, loading gate and hammer are casehardened with vivid, un-faded case colors. The trigger and screws have a fiery niter blue finish. The one-piece walnut grip is oil finished. The ejector rod has the early "bullseye" head, and the hammer has elongated, bordered knurling on the spur. The distinctive, block letter "H.N." inspection marks of Ordnance Sub-Inspector Henry Nettleton are boldly stamped on the left side of the hammer, underside of the barrel, bottom or the frame above the serial number, trigger guard below the serial number and side of the cylinder. A block "N" is stamped on the right heel of the grip and on the barrel below the ejector housing stud. "P" proofmarks are stamped on the side of the cylinder and on the bottom of the barrel ahead of the "H.N." mark. A crisp "US" property mark is stamped on the left side of the frame. The left side of the grip is stamped with the date "1878" above the Ordnance final inspection mark which consists of the script initials "JEG" (Ordnance Inspector Capt. John E. Greer) with an oval border. The lower right side of the grip is boldly stamped with the Ordnance sub-inspection mark which consists of the script initials "HN" within an oval. The top of the barrel is roll-stamped with the third style, "bold block letter" address "COLT'S PT. F.A. MFG. Co HARTFORD CT. U.S.A." This address features a broken "T" in "PT" and has double lines under the "o" in Co." The left side of the frame is roll-stamped with the Colt three-line/three-date patent markings. The assembly number "765" is stamped on the inside of the loading gate. A Colt "S" inspection mark is stamped in the hammer well, and "C" and "G" are stamped on the barrel below the ejector housing stud. The rear face of the cylinder is stamped with a block "P" and block "H". The full serial number is stamped on the bottom of the frame, trigger guard and back strap. The partial serial number "8867" is stamped on the barrel beneath the ejector housing and on the side of the cylinder. All of the visible serial numbers match. Provenance: The Corner Stone Collection