I must confess, when I first posted the request, I was fearful that the tune would be a dud not worth bothering others about. But I'm pleasantly surprised. It bears similarities to a regularized "The Water Is Wide" (O Waly Waly), though not in a way that jumps out at one. This latter tune has been an earworm for me for at least 30 years, and I would have learned the song if I didn't already sing a different version of "O Waly Waly" to a less common (but I think more starkly dramatic) tune: see Gems of Scottish Song, or listen to June Tabor's ripping version. So now I'm in a bit of a quandary, because all three tunes are too good to pass up, but I get easily confused when there are large overlaps in lyrics. I think I'll hunt for a good broadside text that would match this tune, and perhaps concoct my own version of "The Water Is Wide".

leeneia, you're welcome, and Robyn, thanks again!