That collection of names rings a bell. I saw a package at the Free Trade Hall, Manchester in the late 70s that included the Thad Jones/Mel Lewis Orch, Freddie Hubbard, Richard Williams, Jimmy McGriff and Jeremy Steig - no Kenny Burrell, though! I don't remember the year, just the month - November - as fog at Manchester Airport had separated the band from their uniforms and charts, so it was jamming in informal dress. What date do you have for the recordings? Were they taped live at a concert somewhere?