I've noticed that Leadbelly also sings this song on a Folkways record for children, now out on CD. If anybody has this, maybe they could give it a listen and let us know if that throws any light on the words.

Hey, I've just looked at the review on that link, and it says the CD includes the lyrics of all the songs - so you don't even needs to listen to it to help out. (Though I wish I could. I love the idea of Leadbelly with an audience of children.)