In the interests of restricting myths to their proper place (that of informing political activity) let me clarify Alf MacLochlainn and Eddie Butcher and the folklorist's view of "My son in Amerikay."
Hugh Shields describes the episode and its sequels in a slighly arch style in a paragraph in an article "Printed Aids to Folk Singing 1700-1900" in Mary Daly and David Dickson (eds) The Origins of Popular Literacy in Ireland: Language change and Educational Development 1700 - 1920 (Dublin, published jointly by the Depts of Modern History at Trinity College and University College, 1990.) [My explanations. JM]
"In the summer of 1968 a Dublin Librarian A sang a comic song in traditional style, a song of his own making, in my house in Dublin when a traditional singer E from Co Derry was staying with me. E was greatly taken with the song and wanted to learn it; A resisted blandishment as though exercising rights of ownership. The conversation moved on and the song was temporarily forgotten. I met another Dublin librarian P known for the hand printing of ephemera, whom I asked to get and print the song text. Which was done. [and published in Dublin by St Sepulchre's Press] I sent a copy to E which included comically amibuous indication of an air, ["To the air of the Rocks of Knockanure" - Rocks of Bawn? Valley of Knockanure?] and the next year I recorded the song from him sung very much in his customary style. When E became so well known that 'they' came looking for him form over the water, A's song found its way onto a record of E's singing, the label of which proclaimed 'all tracks traditional'. The record was published in 1976 from tapes made about a year earlier." ["I once was a Daysman" Free Reed FRR003]
So the whole story is really an "insider" folklorist's joke about "outsider folklorists. Or is it really a story which reduces the concept of traditionality to its proper absurdity?