I went to all the clubs that John mention and remember Tiny Craig and Dave Watts from those days. Also a harmony group called the Four Square Circle and someone else who was always introduced as The Singing Undertaker. The first time that I saw The Yetties was at the 'Old Tiger's Head' when they got everyone to put chairs against the wall and turned the end of the evening into a dance. There was folk clubs at both the 'Old' and 'New' Tiger's Heads and one I often went to was at the "Rising Sun" at Lee Green run by Dave Cooper.
Tina and I ran the "Tramps & Hawkers" folk club at a pub on Blackheath Hill. I can remember that it was a Courage pub but I cannot remember the name. This was from 1966-1968 when we moved to Sussex