The component parts for the Colt Hartford-London Dragoon Revolver were manufactured in Hartford using Third Model and also some Second Model Dragoon parts (mainly the square-back trigger-guards). These parts were shipped to London and the revolver was assembled and finished at Colt's London factory and sold circa 1853 through to 1857. Approximately 700 were assembled in a serial range from 1 through to about 700. The lowest number known at this time is serial #2 and the highest is #695. As many as 200 revolvers were returned to Hartford in 1861 for use in the Civil War.

The most common address is ‘ADDRESS SAM' COLT NEW-YORK CITY’ with a dash either end or brackets with a finial at either end. The rarest address is hand-engraved ‘SAML COLT LONDON’ (only three recorded including #2 and #3) found on very early specimens or hand-engraved ‘COLN COLT, LONDON’ (only fifteen recorded). The left side of the frame on most cases is stamped ‘COLTS/PATENT’ whilst on some it is hand-engraved (thirty eight recorded). The cylinder is roll-engraved with the Texas Ranger and Indian scene.

British proof stampings are found on the breech end of the cylinder over each chamber and also on the left side of the barrel lug with a crown over a V and a crown over GP. Most revolvers are blued with case-colored frame, hammer and loading lever with silver-plated brass back-strap and trigger-guard. A very few including #13 and #20 are known to have gold-plated grip-straps. The grips are of one-piece varnished walnut and some feature select walnut. A few grips (including #2,#3 and #125) are known to have a screw assembly which was done at the factory to reinforce the grip to give it extra strength. A few revolvers will be found with Second Model square-back trigger-guards and other left-over parts from earlier revolvers.

Pete Holder and Philip Boulton of Southampton, England have collated and recorded a survival rate of at least 27% of the original 700 production of Hartford-London Dragoon revolvers with 37.5% of those recorded to be factory engraved. Overall the percentage of engraved London Dragoons would probably be less than 37.5%. For in-depth reference on Colt Dragoon revolvers see ‘The Book of Colt Firearms- 3rd Edition’ by R.L. Wilson.