"What a shame that more recordings were not done in the fifties and those that were done by the BBC were re recorded over to save money."
No they weren't.
They were filched and re-issued by Peter Kennedy, but a full set - now digitised, can be accessed at the Vaughan Williams Memorial Library at Cecil Sharp House - London.
Not to say that they are in the best of health, but last time I was there they were still listenable.
Jim Carroll