It is cool and interesting. What caliber is it?
I like the idea of a demonstration video, but I'd suggest a nice juicy grapefruit, rather than a toy stuffed animal as the target. I'd think you could do it safely by screwing the lag-bolt mount into a 2"6", pointed in the direction of a safe backstop. Set up the grapefruit at a height centered with the muzzle, and use a wire to poke a hole through the grapefruit. Then mount a pulley at the muzzle end of the board, and run a heavy line around the pulley, through the hole in the grapefruit, and tied to the bait hook. Naturally, you wouldn't load and cock it until everyone nearby was behind the gun. Then you could safely pull the line from behind the gun, with your video camera off to the side capturing the show.
If something like that was available today, it would be a product liability lawyer's dream. I could see nca225, rocky mtn bill, or ed good tugging at the baited hook... unable to connect the dots, and proving Darwin's theory.
