Richie: carry on flattering me like that and I might even learn the ballad. Mrs York's is certainly a fine version. Thanks for posting it.
Steve: I agree that broadsides so far elusive might very well have existed. Someone at some point has written the 'Hind Horn' ballad based on the medieval epic, just as someone wrote 'Bramble Brair' based on an old tale from Bocaccio. Not sure on the detail of 'Earl Brand' - just going on the title Sharp gave in his book - and having used the title 'Cruel Ship's Carpenter' for all those 'Gosport' descendents, he isn't always reliable.
"their predecessors had might well have been much more sophisticated."
Not so sure about that. The migrants (as I understand it) were mainly from the wild border territories between England, Scotland and Ulster: poor, lawless, feuding, and all the rest. Sophisticated, maybe not.