Also, it looks like the 1873 model but on the left side of the frame just below the cylinder it says Pat. Sept. 19, 1871 Pat July 2, 1872. Were they just rounding up or was mine some older model not listed?
Since no one else addressed this, I will. ANY 1873 Colt (original or clone) that is dated will have the 1871 and 1872 patent dates. The 1873 in the Model 1873 name refers to the year the US Army adopted the Colt, not the year it was patented. They could not have tested it and accepted it before it was invented, right?
Also, Single Action Army technically refers to the 45 Colt models with the 7-1/2" barrel, but has come to have the same meaning and is applied to all the Colt Model P Single Action revolvers and lookalikes. Peacemaker was a later marketing name that Colt thought up.