Thanks for the compliments re "Fulstow" Simon, and thanks to Les for posting the lyrics. You certainly don't need our permission to perform the song...we'd be grateful. (Especially if you fill in the PRS form!)
If you can get hold of a book called "All Things Lincolnshire" you will find the story, lyrics and transcription of the song in standard notation, although I believe John actually uses DADGAD tuning.
BTW, get well soon John!