I just bought a rim to use as a trunk spare for my GT500. The four on the car have a dark charcoal accent to the indents and the non chrome areas by the lug not holes. The original rim that I just bought does not have the charcoal accents. Possibly cleaned and re chromed a while ago? Not sure. The accents look original to my rims, but it isn't paint. Is there a blueing process or acid process that they used back in the day? PS I know the acorn lug nuts are wrong. I have new ones from Tony Branda that I haven't put on yet.