I hope that Jim doesn't mind the thread drift, but in response to what Kevin writes:-

As far as I remember, my information about the spread of King Orfeo came to me from a talk at a festival (Whitby?) given by Peter Shepheard. I've tried to find this on the internet, but the only reference to it that I can find you can read by clicking here where Pete writes:-

The ballad is also still to be found in the oral tradition in Norway.

and to bring it back to Ireland.....
I do not speak Irish of Scots Gaelic, but I have been told by those with a knowledge of Gaelic culture that the ballad form is unknown in these languages and that any appearance of it would indicate a translation, most likely from English.