@VirginiaQ Richard Attenborough was President of RADA, not the Royal Academy (of Art).
My relative worked for many years at the RA for the chief executive and I find the Attenborough anecdote rather unbelievable. I don't think they ever opened up for a single vip (yes, for royalty and heads of state and their entourages) but these would all be met and escorted by senior RA staff, probably the president, not the person with the keys. I will check with my relative.