"Steampunk" is a style, not a company. It is just what you see: a retro look using open gear wheels and so forth as used to be common on old steam engines before OSHA niceties like guarding and warning labels were common. Back in the old days, you see, people were expected to understand not to get caught in the gears, even without any assistance from the federal government. To mods, though: most of them I have seen are tube mods, not box mods. There are a few available, but most of them are one-offs, handcrafted, and carry that kind of price. The only production model I know of the the Tesla Nano 100 Steampunk box mod. It's available in copper or bronze and can be found on eBay or any other place that sells Tesla mods.
Just for grins, I looked to see what was available:
I found
this one, a limited edition Borobudur, #29 of 40, and in allegedly new condition. It's only $700.00:
As I say, it is much easier to find a tube mod in this style, if you could live with that form factor. Another option is, they also make steampunk wraps for just about any kind of mod there is.
