If you are researching London folk clubs of that era you would be better researching the Melody Maker small ads. than Sing. Melody Maker's Folk Forum was written by Eric Winter too. But personally never found that to be of much importance either.

The EFDSS was more interested in dance than song and I doubt that they had space or interest in the large number of clubs in the capital. I doubt that many of the B and B audience would have subscribed to their magazine. Some of Ewan & Peggy's club probably(?) did.

Dean Gitter? He was at the club when I first started attending. Another American among the several that came over in the early days of the Folk Scare: Peggy Seeger, Guy Carawan, Ralph Rinzler, Alan Lomax, Fred Gerlach, Sandy Paton and his wife, Jack Elliott, Derrol Adams and from Canada Winston and Mary Jane Young plus of course Pete Seeger when the Ballads and Blues put on a concert at At Pancras Town Hall (which was recorded and issued on vinyl) when he was first allowed to travel.
I have two or three photographs from the Princess Louise days one of which is of Ewan & Penny at the Mic (I am sure this is the night that the BBC recorded proceedings) Seated behind Ewan is Dean Gitter but his face is partly hidden.