Manufacturing began in 1870. This pair are both of the Second Type, featuring the short high hammers and no bolster on the front bottom of the frame. Both have the standard italic Colt marking on top of the barrel and small British proofs on the bottom, with the serial numbers marked on the left side of the grip frames as well as on the inside of the grip panels on both. There are both inscribed "S.M.S.Br.G.C.S.I.J." on the back straps, the meaning of which is unknown. Both of the pistols are also stamped with a number on the bottom of the frame, "3" and "4", on the "A" and "B" gun respectively. They are both fitted with smooth hardwood grips. Includes an oak presentation case fitted for both derringers with a Colt London Agency label on the interior of the lid, key, and a cleaning rod.

See "A".