Thanks, glad there was some useful info in there for some of you.
Paul;
It isn't really necessary to to treat the machined surfaces since they're completely protected by the gaskets once the carb is assembled. Besides, there's really not much you can do for them (the machined surfaces) since you would have to run the whole casting through the entire chemical cleaning process(es) just to get the chromate to take on the machined surfaces, and doing so would seriously damage the rest of the original finish. It's pretty much an "all or nothing" sort of deal.
Eric