Well, of course, Peggy Seeger was quite wrong in stating that the tradition had died out in England but the truth is that, though surviving quite merrily (thanks very much) in pub sessions and village hall dances, it was very hidden. As a child I thought it quite normal that my grandfather played his accordion for ritual dancing, though obviously it wasn't. But the string of performers you name were part of the revival, not the tradition. Lou Killen and Cyril Tawney, as well as performing, did collect and Redd Sullivan's comprehensive archiving of early revival tapes is a fantastic resource but I'm puzzled that you include Owen Hand . . . he was Scottish, innit?