Joe, I think we heard it sung to the tune of Rosin the Bow at the singaround, but that's not the tune being used by Mongrel Folk at the link you posted, and it's not the tune Four Shillings Short use at the other link you posted. To my ears, the Mongrel Folk tune is original, not taken from any other song I recognize.

The Austin Lounge Lizards link just results in "This video is not available".

Thread drift: The Phil Ochs song, Love Me I'm a Liberal, seems to me to follow Rosin the Bow for the first few bars, but then diverges from it.