Hi there! Yes by now they are complete rust crystals in the approximate shape of a cylinder... I have produced a small run of 5 of these S1/S2 swirl pots in aluminum. 3 Have been spoken for so far.
My swirl pots are 6061-T6. the inlet and outlet pipes are bead rolled which is an improvement over the original. My mounting stem is internally threaded to help protect the aluminum threads. One minor difference on this batch is that mine uses a Japanese style radiator cap. I still need to finish them out by welding the little tab for the heater valve.
Shoot me a PM and we can work out a deal
I also have aluminum tube to make the coolant pipes if you are interested in removing all the rust from your cooling system.