Peter Bellamy told a story about the air for this on one of his LPs, where he plays it on whistle:

It seems that it was an old English air that went over to Ireland, where Jean Ritchie (he thought) recorded it from Willie Clancy in the 1950s, and took it back to the US. There Folkways released it on an LP. In due course the LP was exported to England and Peter bought it and learned the air.

Is KYTrad still on her cruise? Pethaps she might be able to shed a bit more light.