1) What wiki calls "received english" is also the accent the Queen uses. She might not be a BBC presenter from the 60s but uses the same pronunciation.
2) Sloaner Ranger accent is just a marginal variant of the BBC spoken by a VERY limited number of people, it is also linked to vocab. more than pronunciation, no?
note: I'm not a linguist and made several assumptions, the main one being that RAH and Sloane Ranger refer to the same cuntspeak.