I use Ammo of Mig a lot on my armour and I have been playing with their new metalic colours also. Those might be of some interest here. Come to think of it their WWI paints for French, British and German tanks and vehicles would also. But thiey just released some thread which I am foing to buy and try. Its Rigging in .01, .02, and .03mm.
http://www.migjimenez.com/en/new-releases/608-rigging-fine-003-mm.htmlI hope its worthwhile. I'm not affiliated btw, just thought it might be of interest. Their web page
http://www.migjimenez.com/en/James