No...there's no bondo....we flew yesterday and we were adjusting the blades with shims and I saw no bondo.
Mike G was at my house last night and we were talking about the blades after I read your post. He does not know Elton's phone # either. I also checked the membership list and he was not on it.
I tried my 23's with the 2 ft hub bar I bought from Chuck (that would make them 24 ft.) and they did not work very well. Lots of shake. With the string, the tracking was off and we could not get it close enough.