This sounds like an interesting and vastly complicated project. To get started, take a look at websites that cater to people making custom computer hardware. It never ceases to amaze me how complicated these things can get, especially the steampunk ones. So essentially, this is not that uncommon of a project, but this particular application is a
bit odd.
My real question for you is what do you want to make it look like? Think about the functionality to awesomeness ratio that you come up with. Take a look at:
The 17 Hottest Steampunk Computer Creations The Hottest Gadgets (10 and 11 are my favorites)
and check out this:
Datamancer.net - Technical Art and Steampunk Contraptions
this dude makes keyboards that are amazing but cost literally hundreds of dollars. These are just a few examples of modded computer gear (exclusively
in one style), and the reason I chose these is that for the most part, these are custom jobs, similar to what you might be doing. These guys cut metal, choose components, and make everything work, and its a lot of work.
A totally steampunk board would be sweet, but I have a feeling it would not be that fast to opperate (touch screens just dont fit into steampunk look). Making the thing usable for someone is critical in for a
console. Also, I doubt youll need a heirloom, custom crafted light board. An
ETC Ion would work fine, and for the cost of some modded/custom work, a GrandMA is probably a comperable price
point. Yeah, it will last 30 years, but by then we wont be using
DMX any more, methods of control will be completelly different, and youll probably have had to go through 2 or 3 boards anyhow.
To make a case for pots or something similar, your probably going to need a CNC plasma cutter or a water jet, or a
laser cutter designed for cutting metal. They do exist, but they are huge and expensive, mainly for military speced gadgetry. If you plan on making a lot of stuff, maybe invest in a plasma cutter, but remember that it carries a lot of the same risks as welding, and should be done only after being shown how to do it by someone who knows how to use it and with proper
safety gear.