Cliff England has the following in his description:
Claypool = H-120-Named After James Claypool Very productive tree of medium height, Quality of fruit is far exceeding all average trees and produces excellent tasting fruit clear juicy pulp with no black specking on the pulp.
I’ve also tried searching this forum here and other threads like this one (Need some help choosing American Persimmons)
Edit: I realized that the thread doesn't actually contain a name - sorry my bad! https://growingfruit.org/t/persimmon-names-and-alternative-names/56920 generally also mention H-120 as being Claypool. Now I do realize that this could simply be a re-iteration from Cliff’s description which is why I wanted to ask.
Looking at the Claypool data itself it appears that C-120 isn’t as highly ranked as H-120 and there appears to be general agreement that H-120 is an excellent variety. I haven’t read much about C-120 so it would be really interesting how it holds up in comparison. It would be strange to name an inferior cultivar after the Breeder to honor his work.