I personally would try getting it to brace height, then work up slow until you have it looking well tillered at half draw. If it survives this far I would back it(rawhide), let it dry for a week or so it get the moisture out, then continue tillering, until full draw.
I have seen unbacked bows from marginal osage break in tension during the making.
The best approach for a stave like this next time you come across one would be to lumberize(plane it flat on the back) it and back it with hickory or boo, make it wider than usual.