Yup! That's the same basic technique used on lots of things. I've used it on my R5 dome and my scrubber droid, though I can't find any suitable pictures right now.
My personal approach is:
Primer. Let it cure; this isn't a race. Pay attention to what the primer is for. You may be able to use a generic "works on anything" primer or you may need to use a self-etching primer - which may or may not play nicely with the plastic.
Satin Black. Putting black under a metallic paint adds depth. Flat black adds more depth, gloss black adds more shine, I like satin as a midpoint. Using a different colour here can have an interesting if subtle impact on the way the metallic paint looks. For copper I'd consider (though have not actually tried) a dark green. For gold colours, a red undercoat is usually better than a black one. In any case, let that paint fully cure before moving on.
Metallic layer. I do a lot of 3d printed stuff so I like the Tremclad "hammered" metals because the paint adds textures that helps hide the 3d printed nature. Not really a factor for you here. Again, make sure this has fully cured before you move on.
Top coat. "Wet masking" with jelly or putty or heck, I use a tube of toothpaste I turned out to be allergic to, can do a great job of siumulating chips in the paint. Salt masking looks cool but I've never actually tried it. And then for edge wear, lightly sanding the part after the paint has dried works well.
Clear-coating metallic paint usually ends up making it look like paint and not metal, so if that's part of the plan make sure to test it on scrap first.