WeeLittleDrummer, you beat me to it, mentioning Barry Skinner.
The very first folk club I ever went to, (modern jazz was my thing, right?) Barry did a spot. He snarled out 'Fanny Blair', the most powerful performance that I'd ever heard, then, or since.

Never been game to sing it myself. It might affect some impressionable young person like it did me.

Barry was one of the founders of the folk revival in Coventry.
Unknown? Then, people like The Furey Brothers, Sean Cannon....