I am. The only model-building* related job that seems to exists in Europe is almost exclusively about building models for production and I'm considering getting into that
*It's about physical models, though.
Look into industrial and product design, it's essentially the same thing. Some guy (or gal- SKG!) somewhere 3d modeled your DVD remote, your cell phone, even toys.
Basically, you have to approach it from the standpoint that regardless of it being made via SLA, or CNC, a combination, or completely by hand- SOMEONE is going to have to put it together. You have to make it easy for them. Adding alignment tabs, pins, places for screws, etc. You have to have places for them to glue it together.
You also have to decide what you actually NEED to model. What parts can be made of laser cut plastic or metal? What parts can be turned by hand on a lathe?
Walls have to have thickness. Enough thickness so that it doesn't collapse, but not so much to make it solid. I get models all the time from top concept modelers/designers in Hollywood- they look GREAT, but they're just paper thin shells- I have to split them up and reverse-engineer them so they can be made- giving walls thickness, screw bosses, etc. It's not that they screwed up or anything- it's not their job to worry about that stuff- it's their job to design cool guns or bombs or robots or whatever.
If it's going to be machined via CNC- the tool can only get certain places, and some detail is just too small to be machined- so it either needs to be scaled up, or deleted. You have to eliminate undercuts- either by modeling them out, or splitting the model up into pieces- but now you have to make it so the pieces fit back together.
For instance, the Reach armor- I have to split it up into pieces so that the machine can get as much detail as possible without undercuts- ALSO, each part has to fit into an envelope thats only 4" tall. The router can go deeper, but while machining steep angles the chuck will collide with the part and mess it up.
All kinds of stuff to bear in mind.