If you think the BBC only destroyed modern recordings, here's a record of another recording destroyed by the BBC.
"On 21 April 1947 he broadcast Shakespeare's Venus and Adonis. It was the most brillant reading. Renee recalled. I listened to it at home. Considering his breathing problems and the length of the poem it was a monumental achievement. Incredibly the BBC destroyed it.
Renee, Robert Donat's 2nd wife, talking about the recording.
Kenneth Barrow. Mr Chips. The Life of Robert Donat. p.157