Thanks, Kretcher and Milosh.
So I mentioned I was working on a tutorial. Here's a bit of a sneak peak on how I did the metal...
First frame - Black Brown base then thorough coat of Old Bronze mixed with Black. When mixing the black with the bronze it takes a lot of black to get it dark enough. On the palette it looks almost black, but when the light hits it on the model you can see there's still some bronze color to it. The matte black will take down the shine of the metallic so we have more control over the shadows.
Second frame - Working in several layers (each with less black and more bronze) up to pure Old Bronze. By the time I get to pure bronze I'm treating it more like an early highlight, so applying it in less places than I would the mid tone
Third frame - Now working with a mix of Old Bronze and VMA Gold. For the areas where I want gradual transitions I work up to maybe a 50/50 mix. Then I take pure VMA Gold and hit some of the edges... the edge of the visor, the details below the crest, the raised line right above the visor, edges of the check guard, etc.
Fourth frame - I've gone over it with some controlled washes/glazes of black, green, and blue (always pushing the brush and paint towards the shadow). The changes are subtle, but I adjust some of the shadows and blends. Those metallic paints can get very light very quickly, so it's easy to lose your shadows. Several layers of washes/glazes can help redefine them.
View attachment 24984
View attachment 24985
Aside from the Vallejo Model Air Gold, all the paints I'm working with are Reaper. But really any dark to medium bronze would work. Matte black and black brown from any line are fine. The VMA gold isn't really like other golds. If you don't have or want VMA Gold, some silver with some bronze mixed into it would probably work as a substitute.
(The images are pretty wide, so in my browser they are shrunk to fit. If you adjust your window you should be able to see the larger version)