While Alice has done a great job, I should add that Peter O'Toole's agent phoned me a response (which is in the other thread. What O'T communicated to Dominic Behan he owed to a childhood learning of the song from one Ned Stack of Kerry which was amended from the recollections of another famous actor and (Northern Irish dialect alert!) drouth, Richard Harris. It has not been possible to establish whether Ned Stack had the song as a macaoronic or what contribution Richard Harris made.