I just had a thought on the Gasket attachment issue.
What if the gasket was glued-in (to look good on display) and could be removed when trouping in hot weather.
My idea is to glue the gasket in place, then put a velcro tab on the inside of each Gasket flap, near the draw-string. When too hot for a gasket, remove the string and flip each Gasket flap up inside the helmet and attach them to corresponding velcro tabs inside the helmet.
Make sense?
Thoughts.
Jono