Try the 2-part Koussevitzky Discography by Edward Young published in the Spring and Fall 1990 ARSC Journals. In particular, the list on P. 77 of part 1 might help.
The Dec. 9, 1944 recording you mention is listed. As to which labels may have issued them, you may have to do some hunting.
From: Association for Recorded Sound Discussion List [mailto:[log in to unmask]] On Behalf Of Benjamin Roth
Sent: Tuesday, January 31, 2017 8:26 AM
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Subject: [ARSCLIST] An Oldie But [very] Goodie
I'm wondering how many different recordings of live performances of Tchaikovsky's 5th are out there with Koussevitzky conducting.
Does anyone know, and does that person have a favorite from those live performances?
I have the one that AS Disc release as well as a couple which I got from Nate Brown.
I just found one recorded Dec. 9, 1944 in Milwaukee (AFRS Transcription).
I noticed that one has to strain their ears to hear the flutes where they should be prominent.
Does anyone know where I can get all the live Tchai. 5 with S.K. or at least the ones I don't have yet?