If it's 'The Dark Island' that I'm thinking of, the tune was originally written for a BBC television series, which is why it was in copyright. It was a great composition, though - absolutely in the idiom, so no wonder Alan Bell thought it was tradtional.

There is a set of lyrics in Gaidhlig, and lurking in my dark cupboard is a version sung by David someone on the Lismore record lable. In Gaidhlig it's called 'An tEilean Dorcha'. I'm sure someone will be able to post those.

Shoh slaynt,

Bobby Bob.