In an aged book about the Hurricane I have a photo that shows what is captioned as a mock up of Hurricane with a barbette on starboard side of the cockpit with 2 Lewis guns contained within said structure. Presumably the pilot was supposed to stop the war change the ammunition drum and then start fighting again. Caption does not say if a second barbette was fitted on the port side.

AND underneath that photo, another photo illustrating a partially complete Hurricane on floats. The Narvik Affair time of 1940, maybe ??