Truthfully, the only place I have noticed the black is under interior paint. The dash was always a not super gloss laquer. In my youth, I was determined that any paint could be waxed and polished to a high gloss hence the rubbing through to black. You can also see on the inner side window trim rings where driving with an elbow on the open window rubbed through to show the same black. If you look under the lower hinge access panels, you see the base black with the blue sprayed around edges. I am trying to remember if I had ever scratched through the transport blue on firewall to see original primer color but don't know that I ever paid much attention.
