Small Scale Military Headquarters

I have the BB Corsair "Eileen." There are little dabs of silver paint around the engine cowl. I've looked at photos of other 1:18 BB Corsairs and seen the same thing.

1. Is this supposed to "be" something, or is it an error?

2. If the latter, is there a recommendation of the specific paint that would be a good color match?

It is supposed to be that way. The silver paint is intended as weathering/wear from where paint would be chipped or flaked off on an actual plane. If you look at aircraft like the Haleakala P-38 or many of the Stukas, you will see the same weathering, such as on wing surfaces where the crew might walk regularly (and this wear/scrape away the paint from the aluminum panels) and near guns and exhaust ports.