Picked up a Martin Denny at the same time - Latin Village/The Versatile Martin Denny. Never seen anything by Baxter or Denny in a charity shop before or since.
Don Ellis - At Fillmore. Awesome big band jazz-rock from 1970. If you like Grand Wazoo era Zappa, you'll probably like this. Indeed, drummer Ralph Humprey went on to play with Zappa. #Jazzsky
Belonging just edges it for me but they're both fantastic. I haven't heard the Carnegie Hall album but then there are a lot of Jarrett albums I haven't heard (the guy was prolific to say the least). I'll look out for it.