There is no question that original billboard Cuda's have the rear side marker bezels painted to match the stripes. "Matte" black (probably similar to, or even the same as the non-textured low-lustre rocker panel paint or radiator side panel paint) appears to be correct for black cars. My own car is a white billboard car, and even though 35 years have passed, the color appears to be Sno-White.
Also, for those who are not aware, the procedure for finishing and installing the rear side marker assemblies is unique:
All Cuda's came down the line and were painted with the side marker BEZELS installed only (No reflector or side marker lamp assy YET), and held in place by the galavanized retainers and "acorn" nuts.
When it was time for the billboard stripes to be installed on a car so designated, the retainers and nuts were removed and placed on the side. The stripe was applied, and during the application was slit to conform to the shape of the quarter panel. The second step was to push the excess stripe material through the side marker bezel hole in the quarter panel and then be trimmed on the inside. The third step was to install a NEW PAIR of PREVIOUSLY PAINTED bezels in the holes, and using the ORIGINAL RETAINERS AND NUTS, which still have BODY COLOR OVERSPRAY on them, back over the studs on the new bezels. These new bezels actually have the words "BLACK" and "WHITE" with corresponding numbers CAST into them. The final step involved the installation of the reflectors and side marker lamps. The set of bezels that came out of the car were certainly re-shuffled back through the system and re-installed on non-billboard cars. Those bezels would NOT have the words "BLACK" and "WHITE" cast into them. The overwhelming majority of used bezels that you will see on vendor tables at the major Mopar events will be this type. Occasionally, used "BLACK/WHITE" bezels turn up. As far as NOS, it is rare to find the "BLACK/WHITE" bezels in the box (I still need the right rear as NOS, but I have an NOS left rear). The bezels are identical otherwise.
My own car is a textbook example of this process. The bezels are painted white (with a bit of primer showing through on the trunk side of the bezels, but NO FE5 Red paint). The retainers and nuts have FE5 Red body paint on them. This was an original untouched one-owner car. I have also examined a great many original billboard cars and so far they are the same.
Does anyone have a pile of used rear bezels? You may be surprised at what you find!
Bill Rolik
P.S.
I will be happy to e-mail photos separately to anyone who would like to see my originals.
bremspts@optonline.net