Manufactured in 1877. The top of the barrel has the Colt Pall Mall London one-line address. The left side of the frame has the three-line patent dates marking. The caliber marking "45 CAL/B" is stamped on the left side of the trigger guard. Per R.L. Wilson in "The Book of Colt Firearms" just over 3,400 standard Colt SAAs were chambered in .450 Eley/Boxer. London proofs are stamped on the underside of the barrel and behind each cylinder chamber. The ejector rod has a bulls eye head. Matching serial numbers are on the frame, trigger guard and back strap. The partitioned case has a Colt London paper label on the interior of the lid, cartridge block holding 24 rounds of Eley .450 cartridges, cleaning rod, James Dixon & Sons oiler, and "L" shaped screwdriver.