Bellow Rifle Mechanism

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Hello everyone I'm currently working on recreating a bellow rifle, but I can't find enough information on the internal mechanism, the barrel, tip-up mechanism, and sights are no issue, but the trigger mechanism and bellows confuse me to no end. I can find vague diagrams of the mechanism but nothing concrete enough to form plans, any help would be appreciated. Included are the only two detailed drawings I could find.