Thanks to Wolf at Magic Com for the picture and information
Roadhouse Blues is a cover version of a song by The Doors. It is unsure whether the band intended on actually covering it that night! Apparently, the opening riff of Waterfront started, something seemed to go wrong, so the band jammed and improvised the Roadhouse Blues until they could jump back into Waterfront!
Thanks to Andre Bergholz for mentioning that Roadhouse Blues was a Door's song. Andrea di Varmo also adds that the "back on the road again" phrase is taken from another 60's band called Canned Head.
The CD booklet contains all the lyrics to the songs (with the exception of Roadhouse Blues) and a brief biography of the group with several other pictures. It's the glossiest bootleg CD I've seen yet. On the downside, it's not a perfect 5/5. The bass is too low for some listeners and there's a burst of static (from the original broadcast) at the end of She's A River.
Disclaimer: I have no connection with Magic Com. I am merely passing on this information to others who would find it interesting.