1972MX22

Hi all, I'm looking for a couple parts from the cooling system, specifically the water outlet/thermostat housing (I *think* the OEM part number is 1633141010), and the "housing" half of the water pump assembly, which I'm struggling to find a part number for. The water pump assy appears to be the pump itself, bolted to a "housing" with some outlets. It's that housing that's corroded. (See attached photos) Any thoughts on where to find these two parts/assemblies? Thanks in advance for any replies.