I've just taken apart a Model C reproducer and it has cork gaskets and a non-ferrous but not copper colored diaphragm (nickel plated). I doubt it is aluminum the center button is soldered. The limit pin is rather crudely soldered (excess solder present) but the rest of the reproducer looks well made. Is it a repro? It had a rather rattley sound and I am hoping that the modern rubber gaskets will improve the sound.
Ron L
