The stocks on the B and Super B are interchangeable! That's nice to know since there's damn few places that have B stocks and several places that have Super B.
I figured it had to be so since the stocks on the Super have the cut for the slide stop post from the B, but the Super lacks the post.
As a bonus I think the wood looks and feels better on the Super B, likewise the plastic on the B. I wonder if Willard will want to swap.