Ok, just substitute that in place of lee enfield. At this years War and Peace I did see a few examples of gas operated aircraft brownings on a few of the stands.
Best to chat to the re-enactors, they are wise to this world. You can shoot blanks to your hearts content.
Maybe build a spits wing section containing the guns, could take it to the airshows, some take their merlin so why note 4 x .303 brownings?