Taking this from the other thread.
"Rarely did either MacColl or Lloyd say frankly that they'd changed anything."
Neither did any other singers in the revival if my memory serves me right.
Can't speak for Lloyd, though I heard that he was extremely guarded with what information he passed on.
All of us who knew MacColl and were in regular contact with him were fully aware that he collated - he discussed it often enough with us and he never suggested to us that what he did rework was 'genuine'.
I know he got a lot of songs from his father, but after a conversation I once had with Salford historian Eddie Frow (founder of the Salford Working Class Library), I came to understand that these were in fragmentary form - quote "William sang dozens of bits and pieces of old Scots ballads at socials and trades union meetings."
I know from personal experience that his mother, Betsy was a singer.
Also, an account of MacColl being 'discovered' as a singer in the early 1930s, from 'Prospero and Ariel' D G Bridson, (Victor Gollantz 1971)
"MacColl had been out busking for pennies by the Manchester theatres and cinemas. The songs he sang were unusual, Scots songs, Gaelic songs he had learnt from his mother, border ballads and folk-songs. One night while queueing up for the three-and-sixpennies, Kenneth Adam had heard him singing outside the Manchester Paramount. He was suitably impressed. Not only did he give MacColl a handout; he also advised him to go and audition for Archie Harding at the BBC studios in Manchester's Piccadilly. This MacColl duly did. May Day in England was being cast at the time, and though it had no part for a singer, it certainly had for a good, tough, angry Voice of the People. Ewan MacColl became the Voice, a role which he has continued to fill on stage, on the air, and on a couple of hundred L.P. discs ever since."

Jim Carroll