"Jim, I thought it started out that way."
It did indeed, but I thought we'd moved on from that nastiness - in fact I know we did
Walter didn't know how far any of them went back - none of us do, but he certainly felt some of them did, which was a tribute to their authenticity, in my opinion
As I have said, he was a prodigious and catholic reader - his choice of books included historical writers like Charles Reide, Harrison Aisworth and some of the classics I have mentioned
His take on history may not be necessarily accurate but it was certainly vivid and he used it to inform his songs
Walter associated his songs - tunes and all - to their historical subject matter - he had more instinctive feel about his songs than any unread folkie I have met - those who choose to educate themselves are a different matter altogether - that's what make them better singers IMO

We once asked non-literate Traveller Mikeen McCarthy, what his oldest song one - he replied, without hesitation, 'The Blind Beggar', a song entered in the Stationers Register some time in the 17th century   
We never told him that, but he mght well have picked it up from the sign hanging outside the notorious pub of that name on Whitechapel Road, around the corner from the site he was camped on
We asked blind Traveller Mary Delaney the samwe question - back like a shot came the answer, 'Buried in Kilkenny' - (Lord Randal)   
The first Traveller we recorded, 'Pop's' Johnny Connors introduced his version of Edward (@What Put the Blood') like this:

“I’d say the song, myself, goes back to.... depicts Cain and Abel in the Bible and where Our Lord said to Cain.... I think this is where the Travellers Curse come from too, because Our Lord says to Cain, “Cain”, says Our Lord, “you have slain your brother, and for this”, says Our Lord, says he, “and for this, be a wanderer and a fugitive on the earth”.
“Not so Lord” says he, “this punishment is too severe, and whoever finds me”, says he, “will slay me, “says he “or harass me”.
“Not so”, says Our Lord, says he, “whoever finds Cain and punishes or slains (sic) Cain, I will punish them sevenfold”.
And I think this is where the Travellers curse come from.
Anyway, the song depicts this, this er....
1 call it Cain and Abel anyway; there never was a name for the song, but that what I call it, you know, the depiction of Cain and Abel.”

One of the most common descriptions we got from the singers we met was "that song is true"
It didn't mean they necessarily believed that the events actually happened - rather, they felt that they might wel have - they felt authentic

As far as Walter's tunes are concerned, I go along with Mike Yates's idea that it is directly related to his memorising them on a melodeon, they certainly were unique
I often think some 'scholars' often over-complicate something that is blindingly simple
Jim