So I bead blasted my covers with some well worn glass bead ... it took them down to a factory silver base coat. The whole freakin front surface is silver ... how the heck did they then paint between the fins black and leave the sliver fins .... I could see how they could do it black first, then silver, but not the reverse.
I have heard of instances where a paint is applied to a mold before the part is cast and bonds with the plastic during molding and also acts as a release agent. No idea if that kind of technology existed back then.
Otherwise, almost assuredly hand paint in some way .. one year part, up option car, no way the numbers would justify an automated process being designed.
