Jim

"The mainstays were 'Lloyd/Vaughan Williams's 'Penguin Book of Folk Songs and MacColl and Seeger's 'Singing Island"

In what years were these published please?

"The best of folk song was to be found on The Third Programme, which nobody but the toffs listened"
Toffs? amongst my family and friends this would have been seen as an insult. It's the first time I have been described as such.
This is the second time that you have mentioned that nobody listened to these programmes. I have no doubt that the audience wasn't large but I believe that the folk audience at that time was mainly interested in the American material which had become more well known via Skiffle. This was available in such programmes for instance as Guitar Club, 6.05 Special, Easybeat and blues programmes made by Paul Oliver.

You mention Folkways which being in New York issued mainly US material. In fact their Harry Smith collection did an amazing job in building a very large audience for folk music. And, it was made up of re-issues of commercial recordings.
Folkways were available in England but only clandestinely or on acetate dubs. At that time they were not licenced for issue here. As a consequence they were expensive. Shops such as Collets and Dobells were raided by customs and the "illegal" product confiscated.