Dear Mick,You can wish me a Happy New Year. I'm sure others feel the same way.
The song you want may be "Queen Among the Heather," a Scots ballad that turns up in Northern Ireland as well.
Take a look at Robin Morton's book, Folksongs Sung in Ulster. Songs 3 is "Heather on the Moor."
Song 6 in Colm O Lochlainn's More Irish Street Ballads is "Doon the Moor." Is that it?
It's possible the Dubliners did the song. However, I think you are prudent to be skeptical of guys from Iceland. I made a career of it.
All the best.