You could still do the pistol grip and I understand that as I shoot better with a pistol grip myself, that won't affect the center shot. But it should be more of a shallow pistol grip, but with the thickness of your handle back to belly, you can do more of a pistol grip.
Yes a leather grip will be sweet, why not just cut up one of your old pursers, LOL. The rest I have is thick leather, like a leather belt, glued together to the thickness I wanted, sanded round and then glued to the bow then the leather grip wrapped around it.