If this is the song I think it is, then I've played it (well, a from-memory approximation) on the mandolin a few times, simply because I think I was playing something that basically turned into it.

Having the tuning GDAE really helps - It'd be a lot tougher to work out a guitar arrangement.

I love that tune. That one and 'Arthur McBride' I think are high points of both Brady and Irvine (although you have to be careful playing 'Arthur' not to do it too sweetly, cos it starts to sound a bit 'Boyzone')