Any pistol gripped butt stock will fit regardless of model as they are all the same (I think even the 39's). The big bore forearms (45-70, etc) will not fit. A barrel band forearm can be cut and re-worked for end caps. There used to be a thread on here somewhere on how to do it but I can't find it.
Good question I asked this a few times and didn't really get an answer. I think the best bet is to get a SET since if you buy a piece meal fore end and rear stock, the chances of the matching are slim IMO. (slight stain differences ect) Also does anyone know where can you buy a synthetic stock set that fits this gun?