For Your Eyes Only Dive Helmet.

CarsonDyle

With a few alterations, I think this could a pretty good prop replica. Bit of an investment though.

danjaq_0ff

Bath play 😁

Too much money, but agreed it would make a good display 👍️

PoorMansJB

There's a US auction house -- somewhat inexplicably in the Mid-West -- specializing in "helmets" who sometimes get the proper FYEO type.