This is a very informative thread. If I may, I would like to add a bit of information.
If purchasing a attachment stock for a Colt-type revolver, there is a difference in the length of the "J-hook" and its housing depending upon if it is for an 1851/1861 Navy or an 1860 Army as the gripframe lengths are different. The photo below shows Pietta revolvers.
Top: 1860 Army 4-screw
Middle: 1861 Navy 4-screw (Stock no longer available)
Bottom: "1858" Remington .36/.44
When I bought my first shoulder-stocked revolver, it was a cased set: Pietta 1851 Navy 4-screw CFS and an 1860 Army stock.
It did not fit well at all, so I substituted an ASM 1860 Army revolver for the set.
I believe that my shoulder stock is actually tiger stripe/flame maple. It is most likely a Pietta, but cannot corroborate that. I have removed the buttplate and the wood is very blond, unlike walnut. I can't believe that Pietta would market a maple stock, so it is a conundrum as far as I know. Any info about this would be greatly appreciated.
Another consideration for Pietta 1851 Navy revolvers is the style of the gripframe. Pietta has produced at least 3 different styles since 1990, which I term:
Large Tail (~2000-2014), Small Tail 1990 (or earlier)-~2000, and Non Tail (2015-present).
As you can see, the geometry of the three different backstraps, including different curves, will affect the fit of a stock to a certain gripframe.
On the Pietta Navy .36 4-screw revolver I replaced the 1851 Navy gripframe with an 1860 Army gripframe and it fits well, at least to my satisfaction. One with a part round/part octagon barrel and one with a Navy octagon barrel:
Another consideration: when Sam Colt was experimenting with 4 different "attachment" stocks for the 1848 Dragoon/1851 Navy/1860 Army prior to the ACW, he decided that a brass backstrap was too soft at the bottom attachment point to withstand the use of a shoulder stock, so all 1860 Army 4-screw and 1861 Navy 4-screw guns were produced with steel/iron backstraps.
I would appreciate any pushback from you folks. I am just trying to learn about these and I am a novice in these matters.
I know this is off topic but we are hunkering down to try to avoid Covid-19 and are about to go stir-crazy, but we have enough food stock for a long while. We have been watching a LOT of recorded movies. We live in a very rural area: my nearest next-door neighbor is 300 yards away so no personal contact. We grow grass hay and oats for the neighbors' beef cattle on 14 acres. It is not a lot commercially, but we take care of ourselves so to speak. Barter is the name of the game here.
I hope all of you folks stay safe, and I am done here with this subject.
Regards,
Jim