Hi Jim
As proposed, a new thread.
(To anyone else wondering what provoked this, Jim and I were discussing this on another thread where it wasn't appropriate so I suggested a new thread. Please feel free to chip in. It arose from a discussion of the depths to which Peter Buchan sank to extend his published versions. IMHO)

I have several books that mention Scott's fabrications and some of them are well-known and widely accepted.

The one that mentions specifically the alterations he made to ballads to please his patron, Buccleuch, is Folklore, The Journal of the Folklore Society, Vol 89, 1978, pt II. It is a scholarly article apparently unsigned for some reason and titled 'The Ballad and History, The Case for Scott' pp229-242.

The author starts by discussing 'Patrick Spens' Child 58, 'Laird o' Logie' Child 182 and 'Battle of Otterburn' Child 161 and the way Scott altered his published versions so that the ballads were more in accord with Scottish history.

The author then goes on to demonstrate how the following 3 ballads were altered by Scott to make the Buccleuch of the period more heroic.
Song of the Outlaw Murray, Child 305
Kinmont Willie, Child 186,
Jamie Telfer, Child 190.