British made and Birmingham proofed key pistol for a lock like Queen Victoria's treasures, 3" round barrel with the key attached, cal. .circa .45 percussion. For loading  the barrel can be screwed out of the frame, the frame with typical engraved, the German silver escutcheon on the grip is not inscribed, engraved butt cap, crisp checkered grip. The metal probably kept in the white and has now mottled patina, the function is good. An uncommon piece out of the 1850 - 1860's period.    $1,650.