The saddle seems like the tree/bars will fit good once he's lost some weight, but the gullet... or hand hole.. I'm not sure which is which~! The hole that allows for withers - is very high up off of him. Like I can easily, easily stick my whole hand in there, because he has basically no withers.
Can this cause any problems? Is there anything wrong with that, besides it looking silly? Maybe that too, won't look so pronounced once he's a bit skinnier and the saddle can come down more...