Further to my above/ below ramble, Whilst having lunch yesterday I raised the Garry Mc, Frank Zappa thing with a friend who happens to be a big Zappa fan and he told me that there were an bundle of tracks recorded during the 1976 tour and a subsequent Live album ' FZ-OZ ' which was released in 2002 and features 'Blind Lemon' Gunston guesting.
Greg.