O'Toole heard it from a man called, he told his agent, who told me, Niall Stack. That this was in Kerry is attested in the same way and by Behan's name for it - The Kerry Boatman. How he came to be there, given the detail in his autobiography, is moot but there are school holidays! Finally, relatively little of Kerry was a Gaeltacht in the 1940s and, even in those regions, many people sing songs in English; as they do today. I'm afraid that nothing that Curmudgeon says persuades me, save that he might take up his own suggestion of asking O'Toole himself.