Jon,
Peter was a very strange person. To write all that stuff and then claim it came from oral tradition. You said yourself a compreaffable posting ago 'evidence of garbled words taken from oral tradition'. He was quite craftible with his compositions and recompositions.

Worth reading Walker's bio of PB. I think it's online somewhere. And this was from one of his biggest apologists. Not a happy man generally. He had delusions of grandeur and wanted to be the next Walter Scott.