Don't know the history, but I DO know that the DT's version for the second verse looks wrong (as are a lot of transcriptions from recordings). Even SingOut recently published the words incorrectly. Here is what the DT has, with my corrections:

A lad I spied by Owen's side yon burn side (a burn is a small creek or brook; SingOut had "barn side" - Good grief!!
And a maiden With a fair maid by his knee
And he was as dark as the very berry brown wood
And she all whey wae and wan to see (wae as in waeful=woeful)
All whey wae and wan was she

The tune has been "regularized", too - on Mick Hanly's version, there are a couple of lovely accidental notes that make the tune a lot more interesting, and I think the tune is printed that way in Sam Henry or Peter Kennedy (my books are at home, so I can't check right now).