By 1973, many of the older buses were being phased out in favour of one man operated bland boxes!
Back to displays...
Hamilton - and this museum is also well worth a visit.
As mentioned on here before, Gaydon has a separate building full of 'reserves' and many prototypes - plus a whole floor of Jaguars, many of which are also prototypes.
Bear in mind that this collection started off at Syon park, as a BMC/BL museum collection, and therefore features many of their prototypes and concepts.