LOL! I don't think it would be legal let alone very ethical in Britain
But the
Stahlhelm was actaually used all over the world. Finland had all sorts of lids, China used them in the 1930s and as a soldier in 1970s Gibraltar I was astonished to see them on the heads of Spanish soldiers when we were guarding the border.
Legally I think you'll get away with it in Japan, helmets are compulsary there, but unless something has changed, anything can pass as one, including pudding basins if the bike press were to be believed.
