Stan,
Colts can be frustrating when trying to figure out a pattern in manufacturing. Colt was not alone in being somewhat frugal as they all were. They did not waste anything & used up what parts they had. Colt had opened a plant in London & the Brits required that all parts be steel & Colt complied. When demand dried up in England, Colt shut down his plant & shipped all the extra parts to the U.S. Thus, he wasn't going to waste those parts so he built U.S. made navies with the extra parts. The 60 armies are a little more predictable & I am a little surprised at the 60 army that you described with a brass backstrap. I have messed with Civil War guns for a long time & never have encountered one with a brass backstrap before. It is a shame it was stolen. The wedge not matching is not a big thing among collectors but all matching numbers are the best. The wedge is the one part that most collectors won't quibble about. It has to be remembered that when several soldiers tore down their revolvers to clean them in the field, it didn't ever occur to them to be sure & match the numbers when putting them back together. It is my opinion that a lot of the mismatched numbers on 1860 army Colts today is because of this. Soldiers had no idea that 150 years later, that some foolish collector would nitpick about numbers not matching. But, a mismatched number pistol will bring much less than one with matching numbers. It is a wonder that today, there are a few weapons that came be traced to a unit or individual by serial number in the Civil War. Back then, no one paid attention to numbers & the military paid scant attention until the defeat of the mighty 7th in 1876. Collecting military firearms is a fascinating hobby but can be frustrating at times.