SN 43831 was made in 1895.
Replacement stocks are available here. http://www.precisiongunstocks.com/index1.html
Don't know where you'll get the metal for the end of the forearm, or the hanger or the mag tube.
You might check with some collectors, before you do anything else with it. Even in that bad a shape, being that old, it might have more value as it is, than it would if you rebuilt it. You might could sell it and get enough to buy a newer gun, in better shape.
Meddle not in the affairs of dragons, for thou art crunchy, and taste good with catsup - George of Lod, Year of Our Lord 297
I always take precautions.
Beware the Evil Bullet Fairies.