When doing the research I concluded it was Walrus, in one of the documents, it actually showed a Walrus, and where the best pieces of polishing wheel hide came from. Winchester tried leather, found it unacceptable.
Believe me…The thought of gluing a bunch of itty bitty aquarium grade sea horse hides together did not appeal to me.
Buffalo/Bison was a huge commodity in this country around the turn of the century. I firmly believe that the bone charr used in period CCH was buffalo bone. Ebonex is the only company still producing bone charcoal; they got their start in the late 1800s supplying buffalo bone charcoal.