Historic recordings- best audio on reissues

Anyone else a fan of historic recordings?  There are some great reissues of classical and jazz performances (and blues) going back to the 30s and earlier. But many of these performances have been reissued more than once on CD. This is partly because it's easy- a lot of these are in the public domain. But often genuine effort is put into improving the audio. Which one sounds best? 

For example,

- A recent reissue of Benny Goodman's famous 1938 Carnegie Hall concert sounds dramatically better than the original Columbia CD because some guy spent a year and a half cleaning it up (which, in turn, sounds better than any LP because a better source was found). 

- There are two releases that I know of for Furtwaengler's 1954 Beethoven's 9th, one a bit better sounding than the other. But there is a CD of a 1955 performance that is just as good and sounds much better.
- There is a "CEDAR" release of Mengelberg's 1940 Brahms German Requiem. How much better is it than the original Philips CD release?

Amazon reviews are not always available for these recordings, this too early for Steve Hoffman's forum, and other sites seem extremely hit-or-miss.  Where do you go to get information? I can't afford to buy all of them and compare!
Take a look at Pristine Classical (dot com). They offer excellent remasterings of historical recordings

Thanks for the recommendation. I didn't know about this.

But it's not really what I'm looking for. They offer a relatively few recordings out of the many out there. For example, they have the 1942 Furtwaengler Beethoven 9th,  but neither of the 50s recordings, which both sound a lot better. And the problem remains: does the Pristine release offer superior sound quality to other releases of the 1942 performance? Hard to say. There are at least three other CD releases of this performance. One from 2012 claims to be the first offering the correct pitch. Does the Pristine release offer the correct pitch?

I'm not looking for places to get historic recordings, I'm looking for places to get reliable reviews of the sound quality of historic recordings on any label.  Any suggestions?
BTW, I am mistaken. I reached out to Pristine Classical once before to ask about their releases and to find out if their CDs are actual CDs or CD-Rs. They never responded.  I suppose their streaming service is their preferred product.