Sorry no tapes but I do remember that the series writer, Ted Childs I think,
came down to Manston and sat in the cockpit of one of the Brits in on maintenance and chatted for a long time with a Dad Newphry, a well respected skipper who told a number of stories/incidents when operating the Brits on cargo charters in Africa.
Some of these tales did subsequently appear in the RED Air TV series which added a certain degree of authenticity to whatever theme the episodes were trying to portray.
As to the RED Air aircraft, I always thought they were owned By Ian Mclean who had previously leased them to IAS Cargo Airline, they being VP and VS and probably BRAC, its original registration eludes me.
Its all along time ago now. Should have written the book at the time. Hey ho.