The song was originally written Gaelic -- that's why she was "Mairi" instead of "Mary" -- for the Mod of 1935.

If that's true, the Mod will have published it at the time, and the booklet will be easy to find, since their annual songbooks were produced in huge numbers.

Anybody want to go and look?

(I think it's more likely that Houston's subeditor screwed something up).