I remember a VC-10 brought Betty Windsor to Rarotonga in 1974, that must have been a perk trip for someone!
IIRC it was British Airways not RAF?
It was indeed a BA Aircraft, G-ASGR (although it should have been G-ASGD but that was under repair after a heavy landing in Antigua) one of the first to be painted in the full BA paint scheme after the merger with BEA. Flight Crew orders were still in the BOAC folders though.