The thing "I don't get" about the Hedman design. I'm an old guy. Those were first made, when? late 60's? certainly early 70's. I HAD a set when I swapped a SB into a 70 B body in about 74?

The point? NO reason why a product that has spanned that length of time could not have been "tweeked" to fit acceptably.

I DO understand the variation in A body pillow mounts, but the OP seems to have spool mounts which should get that part of the tolerance down to a fairly small amount.