1972 Duster Org. paint Resto detail

Ok, here is survivor 1972 duster from California. driver side show small evidence of black but looks more like road grime but hard to tell for sure. Pass. side is a little more interesting. It appears to be painted black almost as if if was spray paint. just wanted to dismiss it as a former owner painted it for whatever reason, but the black phos. bolt is not painted, or at least appears to not be be painted. If it was black spray paint for whatever reason, who would take the time to remove the bolt and paint it? Inconclusive as this point. The one car I know for sure [tb3 blue, Mine] was brush paint and not spray.