Cap'n,
The groups you mentioned - and others - came and went without leaving anything of lasting value to traditional song. Early in the seventies (I have the dates here somewhere, but can't immediately lay my hands on them, Bob Pegg (of Mr Fox) spoke at The National Folk Festival at Loughborough. He was asked by a member of the audience why he performed the way he did; his reply was "for the money". The end result was a pamphlet entitled "We're Only in it For The Money" by Trevor Fisher.
I admired Bob's honesty, but not his motives,
Jim Carroll