.54 caliber, 40″ heavy octagon barrel marked “J.H. JOHNSTON/GREAT WESTERN GUN WORKS/PITTSBURGH PA” on the top.  Engraved lock, brass mounts, double set triggers, plain walnut half stock.  In superb condition with the barrel showing it’s beautiful original brown finish, the lock and hammer have a crisp look with a gray-brown patina.  excellent wood and varnish.  The brass mounts have a lovely deep mustard patina.