I like Roy's idea, that would give me some hickory that i could stack up for a riser.  Roy knows all too well that i'm not a good curve fitter  

LOL,  ya need to learn. Practice with a pine 2 x 2 then use good wood.
I would make the riser 13 inches.

Listen to Roy, he's made AND broke more bows than me...  :D

LMFAO