Were folk clubs of the time not just generally reflecting the usage of swearing in society? So just a matter of art reflecting society?

It was only in 1965 that Ken Tynan uttered the first 'fuck' on TV and even by Sex Pistols time in 1976 swearing was an extreme thing to be done in public or a broadcast or public performance met with shock. Or the reaction of 'it's something common people do who can't express themselves properly' (as an aside it's always seemed the case that education or class or 'position in society' is not a predictor of swearing in conversation). It's weird to think that the first time I heard my dad use the word 'fucking' was in about 1971. He'd been through the war and life but just not something he routinely used though he obviously did know it. I had been aware of 'all the words' for quite some years before that.

Still something of a choice. I don't think we swear when we play live (apart from inwardly when I play bits wrong) whether it's pubs or cafes or wherever. But that's not due to the policies of places but rather something 'unwritten' perhaps?

Here's a joke I told my mother years ago having warned her about the language. Would I tell it in public? - perhaps. The figures need updating! The second is how an unexpected word can have a reaction (about 15 secs onwards). I could tell that in public but I'm not sure how it would have been received in the 60's.

"Two lip-reading deaf guys walk into a pub. One turns to the other and says "You go find a seat...I'll get the drinks in".
He walks up to the bar and says, "Bartender, could I please have two pints of lager?"
"Certainly," replies the barman, "That'll be £10."
"Ten pounds?" gasps the deaf guy, "That's a bit steep!"
"Oh, we've got some music on tonight," explains the barman, "That includes your entry fee."
The deaf guy starts doing the twist and asks, "Is it Boogie Woogie?"
"No."
The deaf guy does his best John Travolta impression and asks, "Is it Disco?"
"No."
The deaf guy shrugs his shoulders, "Well...what is it then?"
"Country and Western"
The deaf guy laughs, picks up his drinks and brings them over to his friend.
"How much were they?" asks his friend.
"Ten pounds."
"Ten pounds?" gasps the friend, "That's a bit steep!"
"Oh, they've got some music on tonight," explains the first deaf guy, "That includes our entry fee."
The second deaf guy starts doing the twist and asks, "Is it Boogie Woogie?"
"No."
The second deaf guy does his best John Travolta impression and asks, "Is it Disco?"
"No."
The second deaf guy shrugs his shoulders, "Well...what is it then?"
The first deaf guy laughs, "Some cunt from Preston."

But I guess it's not 'swearing as punctuation and emphasis' which is perhaps what changed with Billy Connolly and was more like the rhythms of how people spoke day to day or people spoke with friends/in pubs etc? That wasn't there at the time that Billy Connolly was playing in folk clubs in the 60's into early 70's

When you mentioned Swarbrick and Nicol I thought you meant this from Cropredy album