I have come into possesion of what appears to be a pristine Colt SSA. I am concerned that it may be a fake because the serial number does not coorespond to the correct cylinder axis pin retention and the Colt logo does not appear to be in quite the right place on the frame. The logo is also inset in circle, unlike other Colt SSA's I have seen. The cylinder axis pin is retained by a spring loaded push button instead of a screw, but the serial number is 169550, (matching on frame, trigger guard and bottom strap,) which should be before push button retention. The top of the barrel is stamped "COLT'S PT. FA. MFG. CO. HARTFORD CT. USA." and the side of the barrel is stamped "COLT SINGLE ACTION ARMY .45" There is a two line patent and the Colt logo is stamped on the face of the cylinder. The back strap is engraved with the initials "E G" and the grips are nicely checkered walnut do not have external side panel screws. I have not dissasembled the gun yet, are there any internal clues is should be looking for and has anyone ever seen the colt logo stamped with a circle around it ? Anybody have a Colt Encyclopedia that might help?