The original lineup of the four piece was Fran Dempsey (guitar), Pearse Butler (drums), Dermot O'Lenahan (bass) and Ben Weir (vocals and percussion). In early 1974, the band signed with new management and went after the ballroom circuit in a major way. After 1974, we think the band more or less broke up and then was reincarnated as the Butler Dempsey Band which moved into the cabaret scene.
Extract from: http://www.irish-showbands.com/Bands/duffie.htm