All early material was erased, in a deliberate initiative to re-use resources in the 1980's (i.e. recording tape) Radioman (naff BBC £14 million waste of money) automatically deletes everything saved, so many presenters download to a memory stick. I rescued some of my early documentaries on DAT and then Mini disc (another expensive failure) however I subcontracted to my own company and was able to do this. It also enabled my to give recordings to guests for their own use. The government then changed the employment laws, and re assigned self employment as employed complete with PAYE. This wiped out half the payment value of the specialist music shows, NOT the BBC's fault for a change, and loads of presenters moved on to podcasts and other opportunities. After decades at the Beeb I had reached my limit and hope someone younger would be able to take over. Then the pandemic.....end of story. No chance of very many recordings surviving I'm afraid.