i heard someone on this site say they reinforced weak spots with a sinew wrap, and then covered that with thread. in the pic it actually gave it a lot of nice character. it was not boo, but i suspect that wrapping it with sinew is a lot like backing a bow with sinew. one of the main reaosns for using a backing is to hold down splinters on imperfect wood so i can't see why that might not work. best of luck to him.