It varies from plant to plant. Some use one each, some use both plastic and some use all metal. It is very common to see the battery side on Baltimore cars as plastic or both plastic while I rarely see plastic on Leeds cars as an example.
Overspray on the underside of the hood is also common though this one is really heavy compared to most that I see.
Very nice original car. I see the lack of chrome trim on the bucket seat bottoms. Curious about that as I normally do not see chrome on seat bottoms of SS cars but do on Malibu's.
