Cool piece. You won't be able to "cast it", as there are blind passageways. I'd scan it with my NextEngine scanner, pay someone to make a usable solid model of it, then work on carving out the passageways for the coolant and intake flow. If the CAD works out, you could get them CNCd from billet. I'm not sure there's cost savings in molding, as the end product is going to need CNC work for the bore and each face.