Do you know about the Mothers 1970 set:
https://www.amazon.com/Mothers-1970-4-CD-Clamshell-Box/dp/B0884CJNRZ
Four CDs from the early Flo & Eddie era. First disc is previously
unreleased studio recordings from a session at Trident Studios in
London. The other three discs are live, mostly coming from audience
recordings that Zappa taped using microphones set up by the
soundboard. Most of the sound quality on those discs is bootleg
level, but there's some interesting stuff on disc four.
-- Bob