I'd love to see the results when you've tried this out, by the way. A finished piece would be good, but I'd be just as interested to see various experiments on spare parts if you're going to practice different techniques a few times first. I'm thinking of putting this silver/bronze treatment on parts of my chaos lord to differentiate him a bit from the rest of the army, but it's important the bronze aspect doesn't stand out too much over the silver (to fit with the general scheme I use)
I actually tried something along these lines a while ago for a different project and one of the things I tested was agrax earthshade straight onto silver. The wash didn't stand out too much so I imagine it would take several washes or something else to get the look on that Curze model. Maybe silver base with black glazes to darken the recesses, then a few washes of AE, but I think I'd try tin (vallejo tinny tin) glazes rather than AE. Initially, at least.