I remember the first time I heard this at a Pete Seeger concert inSt Pancras Town Hall many years ago - first time I'd ever heard Pete too. Lovely, and most of the sound coming from us, as is Pete's way.
Only thing is, he told a story about a mondegreen (though he didn't use the word) he'd encountetred with this song, with people singing "It was Willie walked up drownded from the Deep Blue Sea".
And I think that's one worth singing - gives the whole thing an eerie feeling, which fits in with the rest of the words. Try it some time. Mistakes like that are how songs grow and deepen sometimes.