Steve, love, Ribold and Guldborg and Earl Bran are the same story. And they both include the informant Carl Hood whom we don't see in the Douglas Tragedy at all. You mean to tell me that with all those Vikings assimilating all throughout those parts, not one could ever translate or teach a ballad to the natives? No. They had to wait for Jamieson's translation to do anything at all. Think about how ridiculous that line of logic really is, Steve, my knight in shining armour :-)

There's a statue of Sir Walter Scott in Selkirk, home of the Black Douglas, because Sir Walter put them on the map. Who knows? Maybe he wrote the Douglas Tragedy himself. He certainly could've. All he would have had to do is get Mr. Sharpe to agree to be his "supplier." Easy.

And I think also that the last verse about Douglas pulling up the briar is telling. Douglas was anti-Jacobite. I think this particular treatment of the the motif might be pointing to the fact that the motif was recognized by some as having been attached to a Jacobite love ballad of small stature. There is one version of the Douglas Tragedy that does have the love knot:

These twa grew, and these twa threw,         
Till they came to the top,
And when they could na farther gae,
They coost the lovers' knot.

For the most part in Douglas Tragedy, however, there is no love knot and technically this not the correct motif as it only meets 2 out of 3 of the criteria. Had there been a love knot, it would have been impossible for the Black Douglas to pull the briar up without also pulling up the rose.