Produced in the 1850s by William W. Marston, under the Union Arms trade name. Fluted six-barrel cluster, with the bar hammer marked "THE UNION/ ARMS CO." on top and "4" on the underside. Engraved frame and nipple guard, with smooth trigger and a pair of smooth bag shaped grips. Numbers are mixed.

Fine, with 60% of the blue finish, strongest on the nipple guard, with a mixed brown patina forming on most other parts, along with overall spotting and some light handling marks. Grips are very fine, with light varnish loss and scratches. Mechanically functions, but trigger return spring is weak.