Danny:
What I'm hearing here beggars belief. In the case of the Duxford York, surely the passage of time would have reduced to insignificance any radiation from the luminous dials and switch tips (same applies to all our bedside clocks, wrist watches etc, as we all well know).
Not yet. Radium has a half-life of 1600 years, so the 70-yo York will still have its Radium at near full strength.