I was there, too, I think—at some school-building concert in 1973 somewhere. I remember sitting either on folding chairs or a floor like a wooden gym floor, with a raised stage. Sat near the front. I remember how beautifuylly developed his arm muscles were from playing guitar. Great concert. He had such energy and enthusiasm, and of course, Clemens and Sancious were outstanding. Later that year or in '74 saw him in a small club in Brigantine, and went backstage and talked to him.
But as I noted upthread, he sold out (and I was done) around !975 or so.