Thanks a lot Masato, that's most helpful.

It does sound like Cock of the North and it does sound like a Morris jig. I first met the tune on the Albion Band album - I think the Battle of the Field on which Martin Carthy sings The Gallant Poacher:

Come all you lads of high reknown
That like to drink strong ale that's brown
And pull the lofty pheasant down
With your powder shot and gun

And the moon shone bright
Not a cloud insight..........
To a tune very close to JoP

The tune in Dave Townsend's English Dance Music Volume 1 has 8 bars of A music then 8 bars of B followed by what is another 8 bars of A.

It seems odd to play ABA ABA, I am no muscian but it seems like something is missing. And it is a good tune!