1969 small block coolant drain plugs

[427yenko]

I have a set that has an concave head, but I believe that it is an aftermarket plug of some sort. It has a clear zinc plating as well. Do the judges look at these things? I have not heard any discussions on this topic. Is it not something to consider? I am in the process of painting the engine and thought I should try to verify this before I continue. Maybe I should just blast the zinc off of the ones I have for good paint adhesion and not worry about it. I appreciate everybody's help on this.