An English 54 calibre underhammer percussion rifle with 'takedown' butt

An English 54 calibre underhammer percussion rifle with 'takedown' butt, round barrel 28.5 in. with one standing and one folding leaf sight, seven groove rifling, Birmingham proofed, acanthus engraved action, the hammer drawn down by a knurled button, later trigger guard, wooden pistol grip, detachable butt (also later) with engraved brass plate.