"...suggest some well-known examples of songs with insider knowledge from the general corpus of English traditional song"
Any ballad containing folklore that predates the subject becoming an established discipline will do for starters - thumb your way through Wimberly and show us where a - say 18th century - ballad hack would go to for such information - the local lending library maybe.
Take any of the sea songs that refer to working practices on board ship - the whaling songs are a prime genre.
Simple example - the "dead-man's face" which is found in Banks of Newfoundland - would a hack be aware of it's significance, and even in the remote chance that he would, why should he write it into a song that is to be sold to landlubbers who wouldn't have a clue what it meant?
Listen to Sam Larner describing the meaning of the term "just as the tide was flowing", or any similar one used by fishermen.
The same with agricultural songs - The Mowing Match, for instance or any of the weaving songs.
Are you seriously suggesting that the broadside hacks referred to a library every time they dashed off one of their ditties.
The information contained in many of our traditional songs, far from being "easily accessible", had not even made its way into print - detailed social history necessary to provide such information of this sort just didn't existy at the time.
The use of local vernacular in any of the country songs was genuine enough to fool the singers that the songs were locally created.
These show a familiarity with the subjects which outsiders would have to make lifetime studies of before they could reproduce them with such conviction - look at Masefield's cack-handed efforts (and he spent some time at sea) - or any of the literary attempts, sometimes of our greatest writers, to imitate 'peasant speech'.
Folk songs do all this with ease, which makes their creators (according to you) far from "hacks", but rather, geniuses who outshone some of our greatest literary creators - how come these geniuses manged to remain anonymous and unrecognised?
I'm sure you are aware of this quote - one wonders why the poor lady (James Hogg's mother) got it so wrong.
"His mother, Margaret Laidlaw, was an unlettered folksinger, and it was she who spoke the famous words to Scott which make a fitting comment on his work: "There was never ane o' my songs prentit till ye prentit them yourself and ye hae spoilt them a'togither. They were made for singin' and no for readin', but ye hae broken the charm now, and they'll never be sung mair.""
You are contradidicting evidence from contemporary writers who would be aware of the mechanics, or at very least, some of the practices of the broadside trade - Hindley talking of the songs moving from "the country, to the presses, to the streets", Issac Walton's "country songs hanging on the walls of inns" - even Child's "veritable dunghills" - all suggesting that these writers were making a clear distinction between orally ccreated songs and broadsides.
"Sharp was discredited with this stuff a long time ago."
As far as I know, neither Sharp nor Motherwell have been challenged on this specific point - perhaps you might enlighten me with a quote?
"all the people who are happy to accept my hypothesis."
You are substituting argument and proof with 'royal patronage' - you are not even dealing with the fundamentals of your argument - try start with explaining how a mainly illiterate population could create such an extensive traditional song tradition from the printed word, which they had virtually no access to.
So far you have been unable to present one sigle example of a traditional song that definitely originated on a broadside - smoke and mirrors Steve.
Jim Carroll