1° "Scottish" of course, I goofed. (I had been working, before submitting my message, on an Irish text...)
2° Origin of the text: Flora McNeil - Album "Craobh Nan Ubhal" (via Geocities)

http://www.geocities.com/celticlyricscorner/macneil/craobh.htm#morun

I am not very conversant with modern singers. Is Flora McNeil identical with the Flora McDonald you mention? Is the latter somehow related to "the" famous Flora?
Although I also found the Gaelic text with a word-by-word translation
at a Capercaillie site, the Geocities lyrics are more comprehensive, but incomplete: the additional verses quoted are only in English. Maybe they were discarded by Capercaillie because they sound somewhat ridiculous as they extoll questionable qualities of the defunct (a heavy drinker who never got drunk, self-refraining woman-chaser...). I would be pleased to find these lacking Gaelic verses.
3° I followed in my transcription the melody line adopted by Barry Taylor. I remember that he puts his version in relation with the Fraser Collection. (By the way, I took your advice and ordered a copy of it!).
Concerning the requested accuracy, I want to plead not guilty. I cannot remember precisely what compelled me to gather the songs pertaining to the Jacobite rebellion, nor what was my aim in doing so. But I certainly did not intend to compete with professional historians, writers or musicologists, since this topic is at the crosspoint of these disciplines. My approach was more "creative" than "documentary". In particular I wanted to convey to a French speaking audience the poetic contents of these pathetical songs through apt translation of the texts and original sequencing of the tunes. An Internet site, combining word and sound, was the ideal medium. That's why I did not pay too much attention to quoting sources etc... You make me realize that more accuracy would not harm my plan and I'll keep it in mind in a future.

Since "my" tune is not the best version, according to John Lorne Campbell, I am in for searching now for the sound recording accompanying his " Gaelic Folksongs from the Isle of Barra". Can anybody help?

Anyhow, thanks so much, Malcolm, for your exhaustive and precise hints.