Troy, just build a new bow like the one below, get some rebar to hammer out into a point and some 1″ diameter, 5 foot long bamboo for a shaft. It will make getting your 40%+ FOc arrow easy, and easy to tune. The bow is about 4″ wide at the grip, with no shelf. You won’t need any fletching to reduce you finished FOC. Works for them!
p.s. You’ll have a tapered shaft too!