DVR and The Hudson Dusters - Verve Folkways - maybe 1968?
I'm pretty sure I still have a copy of it somewhere. It was certainly a different sound for him at the time, using bass, drums and some electric guitar. It had some songs that I guess I would call comedic, like Romping Through The Swamp, or Head Inspector. Probably safe to say it was his least "popular" album with folky listeners, although it has 2 really great recordings on it; Dink's Song, and the best version of Joni Mitchell's Both Sides Now ever recorded by anyone. The book that Elijah Wald put out ("The Mayor of MacDougal Street"), which - if I recall correctly - was largely written by VanRonk, praises it.
But it's not the Jugband LP, which I don't remember ever hearing. You'd think in these days of instant internet gratification, there'd be a copy out there floating around.