How about Rob's Upholstery in McHenry, Il. ?
you can buy those big dog chew "bones" and soak them in warmI'm looking for a small piece of rawhide for my wife to make a holster for my NAA Ranger II.
So far no luck. I haven't tried the muzzle loading sites yet though.
I don't know what size you are looking for, these folks have drum covers to whole hides. Good people.