"Did the British Folk Song and Dance Ensemble exist? Were MacColl and Lloyd involved with it?"
No idea if it existed - Bert and Ewan certainly weren't involved.
Personally, I think it was more likely to have been an EFDSS idea. I think MacColl assisted Ralph Rinzler to record Michael Gorman for and album called Irish Music in London Pubs, but I don't think it went any further than that
Cap'n,
Ewan and Peggy were professional singers who were booked all over the UK. They organised tours for themselves (Pat did a couple for them at one time) and they played to packed houses wherever they went. At the Spinners Club in Liverpool, where I first saw them, it was necessary to book a couple of weeks in advance in order to be guaranteed to get in, Manchester (MSG) was the same. Sounds fairly successful to me. They didn't like festivals, though they appeared at Keele once - Ewan said "never again".
As far as songwriters were concerned, don't know when he made the remark but Peggy edited the New City Songster for around 20 years which included compositions from songwriters from all over the UK and Ireland;
WLD contributed a song to one issue.
Jim Carroll