I am no expert, but the shape of the horn with the lobed top is Native American? I also wonder about the scrim. It is primitive (but totally cool), but it could have been done my Joe Farmer sitting in the cabin at night before bed.
I am taking nothing away from an obviously beautiful horn. Attributing "Native American" to it does not make it more desirable in my eye. I think it is desirable no matter who made it.
Just my 2 cents worth.
Best wishes, and God Bless, Marc