Charlest,
Go back to 123bowl.com and check out the Ebonite blue urethane CRUSH. It had the beginnings of the type of core back in 1993!
Don't think it had the added densities then (1993), but the basic shape and principle were there.
Almost certain it was also used in the original A.M.F. Bull Whip, even though the core pics there show something else ( core from the Whip Lash). I had the original Bull Whip, and it was a really good ball. Liked it enough to do the research back then, and I know I remember what I learned. A.M.F. never used that core configuration again, and a couple years later, it turned up back in Ebonite balls again. Been there ever since.
