Thanks to Iain Gent (and others) for the following information:

This tune is considered “traditional” and used to be known variously as "Dr Mackay's Farewell to Creagorry" or “Dr. McInnes' Farewell to South Uist”. It was subsequently adapted for the 1963 BBC production called "The Dark Island", which is presumably where the Iain McLaughlin comes in that  the tune is attributed to in <<ddpub: Ceol na Fidhle Volume 1>>.

There are various sets of words of different degrees of cheesiness and the copyright situation for these is very convoluted. See <<https://mudcat.org/thread.cfm?threadid=36086|here>> for more than you ever wanted to know about the topic.

**NB.** If you're playing this tune at an event that needs to submit a tune list to avoid GEMA (German music collection agency) fees, be sure to write this up as “Dr Mackay's Farewell to Creagorry” rather than “The Dark Island”, or they will hassle you because thanks to the BBC they'll probably think “The Dark Island” belongs to them. Chances are they will never have heard of the other title.