Colocate both RAF Museums centrally at Scampton and let them organise their own flying display weekend. Now that the future of RAF Cosford has been ringfenced, the aspiration of the RAFM to take the whole airfield is a none starter. (Unless flightline training is to become a 'sim').
The Cold War museum is not a permanent structure and could be moved. The estate at Hendon would provide a small fortune if sold. Yes it would be an expensive logistical nightmare, but it has much merit long term.
National Lottery and English Heritage money could be bid for. RAF units within Scampton either move or become a camp within a camp in the manner that Eastern Radar was to Watton or QinetiQ is to Boscombe.