That's not how manufacturing works. Suppose you've got a Toyota factory full of autonomous robots. The dies you have available are useful for one thing - making Toyota parts. Your foundry? It's got Toyota castings. Your raw materials? You don't have any - 100% of the parts at final assembly were made at a different factory. You don't have a Von Neumann Machine, you have a toyota assembly factory. You can't even mix paint in malicious colors because that's not how the supply chain works.
Uh-uh 'cuz 3D printing.