Just remembered, the liner notes say that Triona and Maighread got this version of the song from Frank Harte. His version, with the "numbers" chorus, is an unusual variant; insofar as choruses are atypical in trad. songs, he may have made it up himself. http://www.irishmusicweb.ie/texts/harte.html has some info on the man, and there are threads on him in the Forum database.

Michael