Starting here:
https://www.steelsoldiers.com/showt...ering-Thread&p=2068376&viewfull=1#post2068376
I tried to bring them to market. I do not believe they are economical to bring to market. $200? Even if I made them in mad volume it would have been multitudes more than this.
When I was unable through my efforts, Peashooter and I made the drawings available for free to the public to see if someone else, perhaps someone who works in manufacturing could make them. We weren't even trying to make anything off them, we just wanted them available to people. So far, lots of talk, no prototypes.
I believe at this point that unless you get lucky and find a complete kit, you should just make sure your single circuit system is safe and new. New brake lines, new rubber hoses (I've had more steel brake lines pinhole than I have rubber hoses fail), new or rebuilt airpack, new master, new or rebuilt wheel cylinders, etc.
If your hung up on a dual circuit system, buy a factory dual circuit truck.
EDIT: Didn't answer all your questions.
Yeah, it's not a pyramid. But, it is a complex casting which was then machined. It has liability made into it (it's a brake system component). It's low volume.
It has an AM General part # but I suspect AMG designed it and outsourced it to a manufacturer.