Evan,
I've looked into doing this personally before, since I've done some work at a CNC shop.. (heh) My god father owned one until he retired. I almost scored the smallest milling machine he had, but since it ran on 440 volts, and weighed about 6 tonnes, I passed. (after all, I didn't need to make aircraft parts)
You need a hobby milling machine first. A good one as well. The Cheap Asian milling machines will set you back around 1k - for something that will last more than a year, and has metal parts. (they like to stick plastic tracks and gears in the cheap ones, stay away from those) After all the shipping costs, customs, etc, I still recommend spending a bit more $$ out of pocket, and going with a local (USA/Canada) built milling machine- plus this way you will get a good warranty, and not have to worry about shipping it halfway around the world if there is an issue... (plus it'd be lots easier talking to someone in tech support local, vs overseas, or just getting questions answered, etc)
Than, you need all the cutting bits, which are.. expensive as well. You also don't want to cheap out on this, as they actually produce the cut, and rough (or good) final product, dependent on how much time you want to spend on it. Than there is the table cost, and the vice cost.
Now, thats just the major cost in equipment, there is lots of other stuff you will find you want, like buffing wheels, probably a dremel for something (detail polishing, etc) and so forth.
Than come the locks themselves. I am told expect to "kill" 3-7 locks for each type/model you cut, until you get good enough to not bugger up. If your planning on doing mass locks of a certain type, build a cutting guide/jig (more time and $$$, but if your mass doing a certain type, you want this route) Without knowing where to cut, and having a jig for assistance, each lock will take time and detailed precision controls in cutting and movement.
And of course, there is countless hours sitting there, wondering how the f#&$ to get a good, clear view of item or part X without parts Y and Z flying out, falling out, not operating properly, lock breaking in half from compromised structure, etc. This also goes hand in hand with the paragraph above, regarding "killing" locks.
Basically, IMO, custom cutaways (proper ones) are more of an art form, than tossing some metal and drilling/cutting it. I'm still considering doing it.. One day, but I don't have the finances currently to purchase all the required tools. I am keeping my ears and eyes open for a deal (used, online, ebay, etc)
There also may be a thread on making cutaways, I cannot recall. You may want to take a look around for it.
