Thanks guys. The runups haven't been a problem for me with this ash so far, and if you look close, you can see that the runup that is cracking doesn't go completely through to the belly. It only goes about 1/4" into the board and then runs true.
I think I'll try Eric's suggestion with the serving material. I don't really want to back this bow if I can avoid it. It is more of a novelty bow anyway. The rest is a bear claw sanded flat and mounted to the side of the riser. I narrowed this handle more than my others to help with the side mounted rest. So far it has been a good shooter and likes 1816 aluminum shafts.