Thanks to 70RAIII, one of the guys on the PerformanceYears.com website where I have the Pontiac version of this thread, I now have the correctly plated fan, nut, and pulley on the the correctly finished case (Thanks to 68L30) 1100928 open-face alternator.
The finish he got on the parts is actually the correct cadmium, like the originals, which is more of a satin finish and not as chrome-looking as the clear zinc that is substituted these days for cadmium, by most industrial platers.