The adaptation (Scots version) may well be founded on the story of some Scots laird, but the basic plot is much older and well spread around Europe as a glance at Child will tell. It is even not certain which came first, the English version (The Outlandish Knight) or the Scottish version (May Colven). I don't have much in the way of older printed versions. None of the extant printed English versions predate 1800. It would be useful to have the Boston text.