I think if you look on social media, people are ready now to criticise the Culshaw production. Also some of the singers were then past their prime. However, we only knew that when later recordings turned up. I think people find a lot of Solti's recordings harsh during that era but later on the sound mellowed.
Obviously Gergiev tried but failed to do a studio Ring but it was so poorly conducted with such an overrated orchestra. I do disagree though that there aren't many great singers who could do it in the studio.
Terfel-Wotan, Stemme- Brunnhilde, Kaufmann-Siegmund, Matilla-Sieglinde, Ekaterina Gubanova-Fricka, Vinke-Siegfried. Zeppenfeld-Hunding, Milling-Hagen. They're just some initial thoughts
That could do as a start