Hello Dave et al,
We'd be very pleased to get to lay hands on these, and we're definitely nuts enough to put real guns on airplanes.
You are correct in your observation that we like to make repro parts and information available for others.
I think that the Birkigt gear wasn't used on the Camel.
Regarding identification; I'm assuming that you mean the parts in the first image. Top left- no clue, middle looks similar to a flip up mount for the anti-aircraft sight used on Lewis ground guns, and right looks to be Vickers type in origin but haven't seen it before and its not in my armourer's manual. Does it interact with any part of the Birkigt gear when assembled? I'm not totally certain why your Birkigt gear has the articulated handle. It wouldn't work the Vickers charging mechanism, perhaps its a manual override for the interruptor or intended to clear some jams. It also appears to be a "field" modification.
Thanks again for sharing these with us all.
Best,
William