Tim - yes, Dave Williams was a very influential early 'folk-singer' along with his (eventual) brother in law Mike Sadler. Dave used to sing in the interval at the Yellow Dog Jazz Club in Portswood, Southampton. The local band was the Tia Juana Jazz Band. We used to go there to hear them and our own (i.e. Bournemouth based)Gerry Brown Band Jazzmen. This giving a local singer-guitarists a spot seems to have mirrored the interval skiffle session at Ken Colyer's club in London.