My lord all decked out in Gromril. I combined Tin Bitz, and Mithril silver with a touch of Yellow ink to make up the ancient armor look. Please let me know what I can do to improve.
Well, your interpretation here is fine. It really depends on what kind of metal the armor was supposed to be when it was new. If you are going for a rusted out effect I find that drybrushing Chainmail over a brown base works pretty well. If you are going for a tarnished effect I'd take a green wash to the knuckles and the bolts and maybe some of the crevaces in the helmet where it is copper. I'd use a dark grey where it is silver. Gold doesn't tarnish.
If you are simply going for a pre-Iron age look then I'd just use as many different shades of metalics as you can. Garish is good. And make them shiny. I always picture Dwarfs as overly retentive. They'd polish even the oldest armor.
All that being said, I still think your version is really good. I especially like the white stone in the axe. This picture doesn't do it justice.
This is a great model. The helm's "feathers" could use more highlighting. The metals need more contrast. especially the visor and the axe. You could also spend more time with prep, as the mold-line is visible across the wingtips.