Guys, the stock is fixed. I've shot the gun for a season and some change.

The issue I have is with the chokes. The gun patterns very tightly. The IC patterns near Mod, the Mod patterns like IM, the second set of F/M barrels is the same way, more like XF/IM.

Yogi,
I'm not sure how you headed down the 12 vs 20 path or why I'd need more shot. I'm just trying to kill a little bird at relatively short range. I can't see putting more shot in the 20 beyond the 7/8 oz for dove/quail. In fact, I'm more inclined to shoot 3/4 oz. For phez, I shoot a 1 oz load of #5s with fairly tight chokes and I'm very satisfied with the results of that load. Like you, I've settled on 2 bores lately. My favorites just happen to be the 20g and .410. I may get into the 28g later, but for now, I'm very happy with the 20/410 shooting I'm doing.