Sadly, I think Your answer is contained in this thread :
http://forum.keypublishing.co.uk/showthread.php?t=30443"
Where are the airliners ??. (ignore Concorde!!)
The fact seems to be that Civil aviation is the extremly poor relation to the military. It would be so good to have a National Airliner Collection but sadly the cost would be very likely prohibitive. The size of Airliners is their downfall as the Cosford situation shows.
I am involved with the preservation of an airliner collection (Not Duxford!) and see the Mil v Civil debate around Me. I prefer to work on the civil side but help out with mil when needed.
Here's to the future
M5DND