I used a Sakura Pen-Touch gold pen from an art supply store on my PX-10, supplemented by Testors gold paint with a lining brush (they match well). The Sakura pen does this job nicely.

FWIW and IME the pen is superior to the brush for this task, and I am very familiar with brushes -- have a BA in studio painting. I think unless you happen to be an old timer hot rod pinstriper, using a brush will be sloppier.