Recorded Music and Publications
I found a Japanese Youtube channel with a massive broadcast library from the 1980s.
All info is in Japansese but I searched my favourite composer, Anton Bruckner, and found many rarities.
Bruckner 1 Erich Bergel NHK 1982
Bruckner 1 Sawallisch NHK 1985
Bruckner 3 Matacic WSO 1982