They all need cockpit upgrades don't they? That won't be cheap I imagine.
I don't see why they need cockpit upgrades, it would be a nice to have but can't see why they couldn't be operated as is. It's probably going to be expensive getting them certified for civil use as they have had 30 years worth of mods. Over a year standing outside at Bruntingthorpe in the cold and rain wont have done the electrics any good either, although they have had anti-det runs every month.