You have already posted a fairly good picture of the left side.....I do not see the Colt's Patent stamping on the forward part of the frame, not the .31 Cal stamp on the aft end of the trigger guard. Compare your markings to this gun....
http://www.gunbroker.com/Auction/Vie...217839469#DESC
http://thefiringline.com/forums/atta...4&d=1298845304