In spite of some reservations here and there about the perfromance, this is an enormously important historical recording, made live in Vienna just days before the Anschluss when Germany annexed Austria and unleashed devastating waves of anti-Semitism.
As I understand it, no Mahler was performed in Germany or Austria or other German controlled countries again until after the end of WW2.
The EMI World Records LPs of the late 1960s as remastered by Tony Griffiths had remarkable sound given the source.
Tom in Vermont