I do make parts on request for people, so if you want a custom badge or really anything just let me know in here or via pm. You know I keep getting private requests for real working gun parts - AR15's lately, Coolhand Customs is not a real weapons factory - but paintball is ok:)
About me: I'm a freelance artist for the past 8 or so years, producing a lot of 3d print models, a lot of video game assets and all sorts of things. some of my work is documented on my blog
http://coolhandgraphics.blogspot.co.uk/I'm certainly looking to make some case
parts, which will again be available to others. The costs don't scale UP well though for big items like entire cases, but if you have your own printer which can build that big, why not?
basically anything that's solid, or purely mechanical is ok, you can print working mechanisms today but it doesn't mean you can print out a working internal combustion engine, clockwork type mechanisms and low stress applications of that ilk are fine.
For those interested in software, Rhino would be the package of choice for most people, but you can use any 3d soft really, you just need to know how to use it to get the right results... No reason why you couldn't design a printable Amiga case with an Amiga even, lots of 3d apps for that platform - I started out with imagine 3.0 and Deluxe Paint IV on my 1200 years ago.
In the future of course you'll be also thinking of print on demand PCB's and other electronics... This is an important industry for retro enthusiasts where demand doesn't often justify conventional manufacturing runs.