Yeah, he put a lot of bells & whistles in it:
Two fireboxes made of 1/4" plate steel, continuously welded on all sides of 2' X 2' X 2' boxes.
Doors on each firebox copied from an old wood stove (lift-latch).
Inside the tank where each firebox is welded to the main chamber is a big flat piece of steel on a rod that goes through the back. This is a baffle, and the outer end of that rod has a handle, so you can turn it to adjust how much heat goes into the main chamber.
He welded 3 big barn hinges on the lid/tank.
The main handle is an aluminum pipe floating on a steel rod, so the outer handle never gets hot.
He was going to put a counterbalance on the back of the lid, because the lid is so heavy, but he figured the weight would keep kids from playing around & getting hurt. He said, He and I can lift it, and that's all who have too be messing with it.
The 3 chimneys thread right in the old tank holes (fill hole, guage, and vent).
He put a rotating cap on each chimney to adjust the venting (similar to the one you see on old tractor exhaust stacks). If you close them, no bees or rain gets in when not in use.
Expanded steel for the pig rack.
Everything is great except the wheels were way to small to handle all the weight. It is a beast! Those little tires went "splat" in a couple days.
He hardly ever uses it, so I told him he should fix it up & sell it, but he is a procrastinater.
I gotta find more pics & put a whole post for you guys to see. It's pretty neat. He is much more mechanically inclined that I am. I'm only good with wood.