I agree I would not either. Problem is the stave has very tight rings. Also has longitudinal cracks. It's been a job so far. I've decided to play it safe and have backed it. Now trying to decide how primitive to finish it. I began going for the Osage tribe bow on page 106 of Native American Bows, Arrows & Quivers.
I would think that rawhide was surly used at some time but, I find no info. to verify this.
Thanks again,
Greg