Parsifal is, in my view, terribly difficult to bring off, and most conductors make a mess of it. It is such a mysterious, strange piece.
Any mis-step in interpretation can render it sounding, by turns, pretentious, saccharine, disjointed and even risible or barmy.
Kna is without peer in this work, and in my opinion his 1951 recording is the most successful and fully realised account of Parsifal. The mono sound is very good and you soon don't even notice the sound so transporting is the performance.
No one else can realise Parsifal like Kna, his readings are simply on another, far more exalted level from all other contenders.
I believe that this is his finest rendering.
Here you will find a transcendent Parsifal that is utterly revealing and moves your whole being- a transfiguring experience.