I inherited an old Colt not too long ago. I've been doing some research on it...appears to be an Artillery Model due to mixed numbers on it (4-digit number on frame and a 6-digit number close to the trigger guard). "U.S." and early 1870's patent dates stamped below cylinder. 4.75 inch barrel and "R.A.C." stamped in several spots to indicate Inspector Rinaldo A. Carr. I'm wondering if anyone has anymore information about this gun & where I would be able to find the manufacture date/history on this weapon?