I love Beethoven's Fifth Symphony. It's one of my nine favorite Beethoven Symphonies. The new edition of the textbook we use at my community college replaced the 1987 Concertgebouw recording with Haitink with a 1964 recording by Szell and the Cleveland Orchestra, and that is the version I played for my classes today. Imagine my surprise when the transition motive that is played by the horns during the exposition wasn't played by the bassoons in the recapitulation. Szell must have decided to replace the bassoons (or enhance, perhaps) with horns. I find the doubled bassoon color there such a fine example of Beethoven humor, and I'm shocked that Szell took it out. You can hear it at 5:32 of this film.
Have a look at the score!
There are other bold Szellisms in the 1964 Cleveland recording, like the slow tempo and heavy quality of the Scherzo, and the way the microphone seems to be trained a single violin during the pizzicato section near the end of the Scherzo (to give the illusion of absolute cleanliness, perhaps?).
Here's a wonderful clip of Szell rehearsing the first movement of the 5th. Unfortunately Szell doesn't make it to the recapitulation in this rehearsal, but he does say "that's good" to the brass who play the motive in the exposition. A complement from Szell? I have heard that is rare indeed. Perhaps he was playing for the cameras.