i used VHT gold witha VHT clear coat on mine long before this thread came up, still working great, looks the same as the day i painted it (well when they are washed )
The Red Metalcast is nice, i just painted some rb20 cam, cam gear and valley covers . look great ! (1 can of each to cover all 4 items)
being a long flat item it is difficult to keep the coats thick enough but thin enough for the metalic to shine, thicker wetter coats remove the paints likely hood of being slightly rough in its finish. colour sand and a buff would fix that though.