[Rick Parker]

Pete if you are speaking of the Small Diameter Billet #8579 that had hold down clamps on the cap, they were sourced (cheaply) from an application for an International Harvester V8. Apparently they were one of the few maybe AMC?? that used that diameter cap and the "Male" type towers. Early on I went looking for a better cap and found that NAPA offered one, as did the brand KEM, both with brass terminals (others may also). As far as the corrosion; it may be caused by moisture from any number of sources. As for the center button; I think many of us are using coils producing higher secondary voltages, jumping wider spark plug gaps through wires that produce a fair amount of resistance as a means of controlling RFI. This resistance causes heat, and the carbon button will be the first component to go. Call it the Sacraficial Lamb.
JMO