Also, Mike, was he left handed? Pictures of that era often were reversed, like a mirror image. The pistol looks like the Left side of the G&G pistol, as the right side has the curved cut in front of the cylinder for loading the chamber, ala the Colt. There's a better picture here, showing the left side:
http://www.littlegun.be/arme%20americaine/revolver%20confedere/a%20revolver%20confedere%20griswold%20gb.htm Stan
BTW, production started in July 1862, and over 3000 were made by 1864. Leech and Rigdon made similar pieces, but of poorer quality, and the hammer shape is different. Stan