Brian, thank you so much for being so helpful and thorough. When I arranged the song I deliberately didn't look it up, just to see what came out in the process. In the past I've sung Martin Carthy's version, Walter Pardon's and one I found in a book but now can't remember which, and suspected I would unconsciously amalgamate something from all. As I remember it, Walter truncated the lines of the melody somewhat, but I had no idea I'd done the same to Mrs. Joiner's / Martin's melody until you pointed it out. I'm very grateful, and will amend the article with the new information.