748 seems the obvious choice for Janes. Has any idea been made available yet regarding the contracts? Fuel burn in the right area of operation is not a concern, it will be factored in to the contract price, or bought by the charterer. Hull value of near to nil makes for a low bid price, more than equating to a good overall package price.
In the world of express package Ops, the network I work for has down sized a lot of feeder routes to perfectly adequate aircraft types, yet will happily throw a 757 at turboprop routes with only 5 tonne of freight, where CATII/IIIA/B capability required (More to loose than the cost differential)
Find the right contracts and there is (happily) life in the 748 yet.
Never worked for Janes, 748, or Emerald or the 'new' Janes, but had the pleasure of working Ops with the Budgie, it is a great machine. Long may it and Janes continue.