It was meself that mentioned the copyright of the music with regard to the BBC.

When I worked at the Beeb, the usual contract for musicians included a payment for the performance, plus extra payments for repeat broadcasts - but with the actual copyright of the performance vested in the BBC. This was certainly the case with my stuff, at any rate.

Whether the Beeb is still interested in retaining that copyright after all this time, I don't know - but it might be worth checking. (a) They might still possess the original tapes (b) They were, after all,responsible for the recording session, etc.

Worth checking.