"Scotch" simply may also mean typical of the Scots or related to Scotland. All it would take to make a "Scotch song" might be a setting in Scotland or in "the North Countrie." The stage song may have been composed in London, as Steve suggests.

While it's tempting to see "faut" as the garbled word, which would make the song at least presumptively of Scots origin, it would seem odd to me that a text Scottish enough to include one Lowland word would not include at least one or two others.

We all share a fairly consistent idea of what "traditional" means, but at times it can be almost as misleading as "folk." A song in the abstract is "traditional" if most of its known texts/tunes have been subjected to usually gradual changes over time within a community of some size. But when a specific version is called "traditional," that can seem to imply that it has come down with little change practically from time immemorial.

"Sir Patrick Spens" is "traditional." Yet MacColl's or anyone else's version, including those of the 19th century ,may not be strictly "traditional" in the sense that they are virtually intact survivals of something very old.

Just so we know what we're talking about.