Mr Buyanovsky was certainly principal horn (he did the Mozart Horn Concertos, complete with vibrato, in Prague). I think the orchestra was pretty stable as to personnel and there's a high likelihood they all played on the Tchaikovsky recordings.
Mr Mravinsky was an extraordinary musician (not least for being the only conductor I know who had an ash tray built into the conductor's stand so he could merrily chain smoke his way through all rehearsals) but so, at least live, was Mr Svetlanov.
A label called Canyon (I think) issued Tchaikovsky 1-6 plus Manfred recorded live as Mr Svetlanov toured Japan with the USSR State Symphony around 1990. I'm not saying it is for everyone but if you like exciting and vivid Tchaikovsky aka Mr Mravinsky you might also like these. As with Mr Mravinsky, there is some phenomenal playing. I love Svetlanov's semi-quaver rest between the third movement of Symphony 4 and the finale

Interpretation is always a matter of opinion but the playing of the orchestra is absolutely outstanding. In their heyday, the USSR State was a truly great orchestra in my opinion equal to any orchestra in the world.
I will say, however, that I think Mr Svetlanov was the greatest interpreter I have ever played for of Liadov's wonderful piece 'The Enchanted Lake'.
Kind regards, Alan M. Watkins