"... never managed to set it to music, though, ..."

However, referenced from an old mudcat thread post of 23 Dec '07 by jfw himself:

www.weldonalley.ca/songs/yule.mp3

The song isn't referenced from the main site, but the link is still good. It brings up some kind of local player to play it. (guess it's actually my browser that's providing the player.)
I really like John's tune, and the way he sings it. Don't see the need for another now.
I'll try to make I've made an abc of what I hear.

Link found by chance recently while looking for Anne Lister's Dance With The Dragon on a mudcat thread which doesn't seem to exist anymore. Wrote down the link, but not the thread ID. (maybe some range of posts were lost around 2007?)

    I had originally tried the Yule words with tunes like "Greensleeves" and various Corries songs, and eventually settled on a modified version of Galaxy by Eric Idle and John DuPrez (from Monty Python). But John's tune has become an ear-worm now.

--Bob