Funny enough, ive just been trying to do the exact thing for a nerf gun mod im working on. Check out this tested vid:
https://www.youtube.com/watch?v=3b_0pJTKWGo
In it they paint a brushed steel robot body using alclad laquer. I simply copied the technique but replaced the steel paint with a gold one, i.e. spray with a gloss black base coat, apply a thin layer of metallic laquer, use wire wool or emery cloth or something to brush unidirectionally over the top metallic layer giving it a brushed look, then clear coat it.