Thank you, thank you Big Tim for those lyrics and the information. I, too, heard the song on a Father Sydney McEwan album in the 60s and spent years looking for the words. I'd given up. This was the first Lewis Bridal Song I heard, so the other, more popular Mairi's Wedding felt like a travesty and still does. Mairi's Wedding is a nice enough song, and I've sung it for a friend's wedding, but 'step we gaily' jars with me. That's more because it's a bit too ho-ho-hearty in comparison with the other (Morrison?) song, than because it doesn't sound Scottish.
Richard - I just thought of something re 'step we gaily'/'step it gaily'. Hugh Roberton's Air Fa La La Lo (another ho-ho-hearty type of song, but I like it) has a line that goes 'So step it along as light as a bird on the wing'.