I was taught a long time ago that it was Chrysler-Plymouth-Dodge (I suppose Desoto also) policy that when looking at a car from any exterior angle, you only see body color on the exterior of the vehicle. This means wheel wells and radiator support (when viewed thru the grille or headlights would not show body color. This is why all cars except dark blue or black colored cars left the factory with sloppily applied flat black paint on the outside of the core support and hastily applied undercoating in the wheel wells.
Now, as you look at high dollar restorations of cars and you see the body color either through the grille or inside the wheel wells, they just don’t look right. I do, however, understand why someone wouldn’t what to apply crappy paint over nice paint. I’ve done it to 2 cars that I can think of (’71 Top Banana Yellow Charger and my G). It was not easy at the time when considering the time and effort that went into a nice paint job. BUT, the cars look so much better that way.
As a side note, my white G had never been apart before I got it and the outside of the core support was painted flat black.
on my mostly original G, it very much looks like it was painted body color, and then someone on the line just sort of reached in with a gun or rattle can of flat black paint to hit the area around the radiator that would show through the grill and not look right going down the street.
It doesn't appear that any masking was done, either. Almost like an afterthought to make sure you couldn't see the white body color through the grill.