Saw them all over the West of Scotland. When they were starting out they were more or less regulars at our Folk club "The Alba" in Dunoon Argyll
They even wrote a song about the place, "Why don't they come back to Dunoon"   lamenting in a humorous way about the lack of holiday visitors to the town. Its on Youtube from one of the local halls about the late sixties....if I remember correctly it's just billy and his guitar...our club was held in the Glenmorag hotel ballroom and was packed every Saturday several hundred paying customers.
Tam liked the Bluegrass music, "My Dixie Darlin'" was a big favourite, but Billy liked making people laugh....I never saw him as a "folkie".....just a great entertainer and a nice genuine bloke.
In those days, Billy was just one of a large number of "Characters" who inhabited the folk scene, poets, singers,groups, hingers -on. All much larger than life, and all "life enhancers". great days.