this description goes wild "Dreyse Type (Unmarked), Model Needle Fire Shotgun, Muzzleloader, Single Shot, 12 Gauge (Approximately), 32.75” Barrel, Octagon To Round, Engraved, Side Mounted Cocking Lever, Safety (Paddle Behind Trigger), Checkered One Piece Stock, Shadow Line Cheek Piece, Sling Mount And Button, Steel Butt Plate, Brass Museum Tag, 4 Lbs., 7 Ozs., 14.5” LOP, Serial # 28, "
https://www.gunbroker.com/item/875086340
in fact a Mauser 71 action, looks like a target rifle, maybe a 12 ga for shooting the eagle target