I became excited by Winstanley et. al. through Hill's World Turned Upside Down in the 70s, about the time Kevin Brownlow was creating his movie. Much later, after Christopher Hill gave a talk (on Bunyan), I asked him about the Diggers from the sixties.
I noted, that Emmet Grogan's autobiography, Ringolevio mentions that they decided on calling their NYC group (transplanted to San Francisco) the Diggers after reading an English history book.
I asked what that book would have been since WTUD came out after the Digger moment.
He smiled with delight to remind me, of course, that he had been writing about the Diggers at length at least since the edited collection of documents, The Good Old Cause, in 1949.