Hogg,
You don't know about this great old lady? Transmeridian (HeavyLift 'predecessor) used to operate a fleet of 7 including the 'Guppy' version. I spent many a 'happy' hour down the back, on the bunk or producing coffee & meals. Produced by Canadair, looked a but like the Britannia but was a completely different aircraft, swing tail, could haul 27.5 tons bulk loaded over about 6 or 7 hours if memory serves with 4 Tynes gently vibrating the loadie to sleep. Real old Freight Dog aircraft.
Ah, happy days