To add my 5 p's worth (and without speculating
too much), from experience of EGBB-EGNX positioning flight plans, the trip takes about 10-12 minutes and the fuel burn is around 600 kg for a 737-300 in 148Y seats config. So something roughly similar for a 737-300 freighter with 10T of cargo on board - however, the aircraft may actually not have flown direct due to the emergency.
The aircraft is still at BHX, looking forlorn and slightly lopsided
on the Western apron.
Cheers
