What is correct finish for trunnions?

[Vito Pacione <vito@argohouston.com>]

Does anyone have a really low mileage original car that they can reference
for me?

The front trunnions are brass, but I think that I can see tradces of black
paint on them. It's always hard to tell whether it's paint or dirt after
many years, but it sure looks like they should not be left brass. 

Can someone let me know? thanks!