Actually the trick we have learned for the white VHT, is to paint them white and then use the VHT high temp clear coat. VHT makes a clear coat in the same line of header paints. The clear coat will turn them kind of an off-white. But the benfits to the clear coat, are you can handle the headers without damaging the white, and it produces a semi-gloss, slick surface so that you can wipe off grease or dirt for installation. It is so hard to install clean white chassis headers on an old hot rod with miles without getting them dirty. Clearcoat is the solution. You just have to avoid scratching or gashing the paint. Once the car is fired, it will bake the paint on.
by the time the white VHT starts to look bad, it's probably time to detail your engine compartment anyway. Just pull off your headers and shoot them again.
Here are some white ceramic ones I did for Woodyz Hot Rods By the way, I think the Duesenbergs were Porcelain Coated, not Ceramic.
Never used 'em but i know lots of guys who use the ceramic coated headers and they look great for a long time.