After several months and calling all over the country the gunsmith finally found a mainspring for the pistol. Found it at Dixie Gun works in Tenn. This is an 1838 R. Johnson Flintlock, 54 caliber. Its Marked U S and Middn, Conn. The gunsmith here in Petersburg did such a great job I believe I could fire this thing with no trouble. Hope you enjoy seeing one of the guns from my collection.