I obtained the Bernstein/Cleveland performance, and as stated, the sound is poor, being afflicted with static and other electronic interference (it sounds like a recording made off the air), but the performance is magnificent! I have various contacts looking for a better source recording and await news of their efforts.
Interpretively, I would have to place it as somewhere between his 1963 NYPO recording and the later 1973 LSO recording. It does not compare at all to his DG NYPO digital in-concert recording.
Being as the performance was outside at the music shed of Cleveland's Blossom Music Center in July of 1970, interestingly enough, during one of the quiet passages of the music, you can faintly hear a whippoorwill in the distance. Quite a fitting touch to a magnificent performance! Incidentally, this was Bernstein's ONLY EVER appearance with Cleveland.