Sounds like it was a display/counter pistol. If you are going to shoot it, a bit of steel wool/oil and cold blue/oil will do wonders because you'll put a few (!) more dings in it during its life. Yes, 1860's had a blued backstrap and a slightly longer backstrap/TG/grip compared to the 1851 Navy. I am thinking of ordering a Pietta 1860 backstrap/TG/grip/mainspring for my Pietta 1851 Navy .36 as I have a wide thin hand with long fingers and the standard 1851 Navy grip is a bit short. Pipe dreams.
I have noticed (especially in the Dixie Gun Works catalog) that some Pietta 1851 pistols are shipped with "hardwood" grips as opposed to "European walnut" grips. Don't know if that applies to any other model. The white hardwood grips usually have more figure but are stained somewhat reddish, so if you want to take them down to refinish, keep that in mind, please. The walnut grips tend to be more plain straight-grained with little figure. I have seen some walnut grips that exhibit LOTS of figure on a production pistol. Luck of the draw, I guess.
Congrats!