Not sure if this will help at all. I had re-sprayed the wheel flairs with DBU/CC on one of my 78's, but the more I think abut it, this was probably 20 years ago, so I don't know if this mixing formula will be of any use, but maybe?
I gave them one of the oem painted flairs to match the color
Matching my car might not match yours. but this car has original paint & the flairs looked & still look great as far as a color match.