This issue of the session with Bailey may be easier to find: https://www.discogs.com/release/10312566-Pony-Poindexter-Frank-Rosolino-Fritz-Pauer-Art-Farmer-The-Exciting-Jaz
I have similar thoughts. You have to consider the percentage of women on any instrument. The majority are vocalists or pianists. This has changed only since the 1970's. In this respect Mosaic's releases only reflect the respective numbers among recordings actually released.
That said, there are others factors than gender involved - how many great musicians are under-recorded?
Yep: https://www.discogs.com/release/10456228-Earl-Bostic-Richard-Groove-Holmes-Joe-Pass-Complete-Quintet-Recordings - Bostic, Holmes, and Pass on all tracks. Pretty smokin' sessions, originally released on King.
This is a reissue of an LP originally released on MPS on their Session sublabel in 1970.
That issue and the re-issue both say it was recorded in 1969, but at that time Jan Hammer already was in the USA. 1968 is the date Poindexter shares in his memoirs and mentioned in the credits of a recent ENJA release which has Benny Bailey added.
https://jazzdiscography.com/Artists/pony-poindexter-discography
I have a large format calendar with his works - portraits of famous musicians based on photographs. I even had two of them framed in the living room for a while.
http://www.iliev.de/wp-content/uploads/sites/5/2015/03/joosClarke.jpg
http://www.iliev.de/wp-content/uploads/sites/5/2015/03/joosLewis40x60
https://www.booklooker.de/Bücher/Michael-Naura-Herbert-Joos+Miles-An-illustrated-Portrait/id/A02yHYBA01ZZb
https://www.kind-of-blue.de/seiten/joos.htm
German jazz drummer Ralf Hübner was a painter. Guitarist Volker Kriegel, also cartoons and children's books, IIRC.
What about Daniel Humair and Hans Koller?
I found the documentary on th two DVDs in this box set to be very enlightening.
https://www.discogs.com/release/14700313-Nat-King-Cole-His-Musical-Autobiography/image/SW1hZ2U6NDUwNTI2NTM=
These are the reasons why I will probably rather not buy this set. I still have so much unplayed discs lying around here and filling the shelves.
Plus, I'm afraid it won't fascinate me musically as much as I would hope for. I missed Mingus playing in a local club around the time he record the "Moves" album, we were caught in a traffic jam and arived late when it was already sold out. What sounded up from the basement to the ticket counter was George Adams wailing who never thrilled me so much.
That's the only album of her I have, bought after being mentioned here. Her renditions of old standards sound more sincere and authentic to me than Björk's.