Mr Mole
ALL the removed equipment from the L1011 during their tanker/freighter conversion was returned to the MOD. It used to be stored at Aston Down. The problem being that none of the equipment was labelled up. We went to visit in the early 90's and we counted over 20 wire pallets of equipment that could have been put to use on the ex Pan Am aircraft (even something as stupid as a loo seat).
No doubt all this kit was either sold for pennies or is still sitting in an old hangar.
As for costs i believe the 3 ex Pan Am aircraft cost more than the 6 ex BA ones. There was also tech differences in the aircraft.
Lots of previous arguments about which is the best aircraft for the FSTA, the only thing we all agree on is that it should be "new build".