I think this might have been their appearance in the Grand Theatre 1993.
Taken from a music forum and the subject was Lindisfarne ...
"I also, very fortuitously, caught the tour with The Strawbs (a very fancy bar stage design, as I remember)."
" I was visiting family in Swansea with wife, & we popped into a town centre bar (The Builder's Arms, for anyone who knows Swansea) where - unbelievably - we spotted Lindisfarne playing cards, a table or two away. I - eventually - plucked up the courage to say hello, get some autographs & ask them what they were doing in Swansea and it turns out they were playing a gig in the local theatre."
" Alan asked why we weren't going so we told him we were just visiting town & didn't realise they were playing. He told us the gig was sold out but give him a minute & he'd sort something out. He came back a few moments later & told us that he'd persuaded the theatre manager to let us stand at the back of the theatre for the duration of the show as his guests. Extraordinary! Not only that, but at the end of the show the band came & sat with us for a while in the venue bar to see how much we'd enjoyed it."
"They say "don't meet your heroes but Lindisfarne - & Alan Hull, in particular, were real gentlemen that night."