Thanks much, Reinhard. So far, I've been able to find a piano rendition (quite nice) by Mícheál Ó Súilleabháin called "Casadh Na Gráige" (The Turning of the Road) on his albums Templum and Between Worlds. I'm guessing that's a fuller title of the tune. The only other musical mention of it I've found is to an arrangement for brass band(!). Clearly isn't the usual suspect "Casadh an tSúgáin" (Twisting the Rope).

Casadh Na Gráige also appears to be a place or town in West Kerry, which complicates searching. There is a poem called "Aisling ag Casadh Na Gráige" (A Vision at CNG) by Michael Davitt—unrelated to the tune or song.

Anyone else know where Les and Mícheál may have found this tune?