Bert Lloyd wasn't alone in this. It is all part of the oral tradition. Many of the Scots tradition songs were rewritten by Burns and many Irish songs owe their popularity to people like Graves who rejigged them. Nick Jones was a more modern culprit.

My comments were regarding this particular song.
I can see no connection between Lloyd and the song other than the fact that he sang it.
But when did he sing it --- was it before or after the Elliotts?
Could he have learned it from the man in Bishop Auckland or vice versa.
Was Lloyd ever in the North East??
Was he ever in Canada?

I would suggest that for this type of enquiry a visit to Lloyds collection in Goldsmiths college Library might be a goos place to start.

A.L. Lloyd Collection
This consists of the library and papers of the folk-song specialist A.L. (Bert) Lloyd. The collection covers traditional music from around the world, but is particularly strong on East European folk-song. Lloyd, being a member of the Communist Party, had unprecedented access to Communist States during the Cold War period. The books are catalogued, but not the papers.
Contact: Peter Morris, Subject Librarian for Music.

I would also suggest that this article could offer some answers
A. L. Lloyd and the Search for a New Folk Music, 1945-49