Oh, darn. When you said it was on his Last Sessions album, I thought we'd be able to find the lyrics in the Smithsonian Folkways CD booklet, which are always available online. Didn't work this time, though - the booklet is interesting, but contains no lyrics. I rarely try to transcribe Lead Belly recordings - it's just to hard to understand him.
Keep watching this thread - maybe somebody will come up with an answer.