I wouldn't go by the natural shape as to the bow style to make but split it as to the compression side/tension side and make it(the tension side) the shape you want with a little heat. Split it, remove the bark(and sapwood but that isn't necessary for a successful bow) and seal the back and ends. Even though it was cut last year, with the bark left on it might not be as dry as you think. "An ounce of prevention is worth a pound of cure"! and it doesn't take but a few minutes to seal it. Pat