Rear valance would have very little overspray over the base red oxide typically since it was attached to the car at the top edge and the bottom edge has a fairly sharp edge that didn't need any paint on the edge. There us sometimes a light amount near the ends where some paint should have passed through the reverse light opening (though no direct angle to the surface) but slightly more would have entered from the ends and landed on the back surfaces near there. Have seen them with allot less body color than this example but this is an example of how some of them ended up
The front valance is different since it was painted off of the car and there were a number of edges that needed to have body color on the, So the back side (visible when the hood is open) normally would get a good dusting so that you would see mostly or all body color - just not a nice smooth (exterior looking) coat of color
