Oh wow, does this sound familiar! Just need to add “ripped the seat of the tractor” in there. And when the Mr. Mischief weighs 2,000lbs it gets really hopeless. My horse has turned on the spigot and flooded the paddock, let himself out of the gate, and pulled the plug on the automatic waterer and flooded the paddock several times(I still don’t know how he did this!) just to name a few. Talk about destructive!
Since he seems to like buckets you could give him a bucket that you don’t mind if he destroys. You could even hang it on a hook that he can take it off of so he can bang it around in his stall.
Hope you find something he likes to play with!