Hi Merv
I just re read this thread and realized nobody had suggested HPC coatings to you.
HPC - High Performance Coatings
They do a number of colors in both heat proof and appearance coatings that are way tougher than any of the paint products mentioned.
I have personal experience with the exhaust system on my ultralight and my bikes
I had the exhaust coated inside and out over 10 years ago on the plane and they still look new, no rust, and amazingly no scratches or pock marks from stone strikes.
The coating is fired on in a furnace somehow, check them out.
I have the satin black on the bikes, and the satin Cast Iron on the Ultralight
I also had all the bolts on my A9X coated in gloss black when i rebuilt her, looked like black chrome.
hope that helps,
Dave