It’s too early to say that it will close. The battery gigafactory plans are in a very early stage at present.
Like with all insurance, the premium will depend, amongst other things, on what risks you are insuring against and the value of the item.
Dayglo would have been far too tatty for Queens Flight aircraft. As said by Viscount above, the paint was highly polished bright red. Almost a pillar box red.
The lamp unit appears to be a sealed beam halogen one. Presumably that would make it post war.