On re-reading your message I realized that you were talking about using an unchromed plate, rather than re-chroming. That raises the question for me about where you would get the unchromed plate? I don't think I have seen them marketed.

You could, however, use this process to remove remove the chrome from the whole neck plate. Wouldn't take much time if you have access to someone who does chroming. I used to know a bicycle shop that would do it...