The yellow is actually naked ABS plastic. The original chrome was a vacuum metalized deposition so it left about the same way it went on ( gone with the wind ).
You could pay to have it restored or just use a chrome paint.
I use Duplicolor trim black on that one part. Not that it matters really.I wouldn't use a very high gloss on it.
SEMS is a lacquer based paint, so if you use an enamel chrome to paint it all, you may want to stay with enamel in detailing.