GG, there is a world of difference between storing the Chinook in a shed, they would probably all fit in one, and the Nimrod. The MRA4 would not fit in a standard hangar. The obvious hangars in to which it would fit would be at Kinloss however the Army will need those to store their snatch Land Rovers
You could get probably a maximum of 3 in a shed therefore 3 sheds. BAE has sheds but they would charge a rental too. The cost of ownership therefore is a significant factor and is one reason why so much military kit arrives on the surplus market at one end of the country when people elsewhere are crying out for kit.
Simple example, I needed a paint locker - if stores (sorry Supply) could provide one then it would cost £500. I bought one at my local surplus store for £35. At the time I bought it we actually owned it even! Mad.