kenparry,
I think the problem here is the difference between phosphorescence and radioluminescence. (Wiki has a good entry on this). Presumably elf'n safety is worried about the latter, but I'd always supposed that most of the wartime instruments (like all our watches etc) would have been of the former kind.
I believe harrym may well have been right about the Museum's curator (in that way he'd keep souvenir hunters out and small (and bigger) boys from tinkering with the controls !)
Cheers, Danny.