I have reservations about the format used by this film. Mixing documentary sequences with rendering of real life dialogs by actors involves the risks of theatricality, and seldom or never generates something valuable from a documentary or artistic point of view.
Can I just point out that if you listen at the end of the documentary,they are wishing each other happy 1955! I think you may be getting confused with Toscanini's stroke which happened three years later in 1957.
