Jeff ,
You can produce your parts from metal or plastic.
You have to define that will you copy a camera part or will you create everything from zero.
What would be the size of the parts , will there be screws on it. What would be the precision ? Where will they be used ? How will they be used , will there be a load , how many times they will be used ?
If your parts is less than 3 cms , 1.5 inch , there is a company who prints steel powders with a inkjet printer and sinter. They can produce ten thousands of parts daily. This is called Rapid Production.
If your parts are bigger than this , you can order from shapeways com , metal or plastic. They use steel powder again , sinter and fill the gaps with copper.
Or you can order a metal or plastic part from CNC shop.
As you can see , there are many metal parts production methods. You will need a computer drawing and your part can be draw at a cnc shop .
you can produce it at CNC shop with highest precision and widest range of materials . But this is not cheap.
Other method is to produce your part with rapid prototyping. But this is not extremelly strong or precise.
Only you have to do is to ask your CAD guy to record you a SLA , epoxy layer creation with laser technology file. More layer , more precision , more trouble for your wallet.
If you want a mold and cast your part , you can order from CNC or RP. You can order cnc plastic mold.
If you have the original part , you can order a mold from it with silicon plastic.
Carbon powder added epoxy is good contender for your business.
BUT polymers tends to strech in the mold when they hardens and this must be calculated.
Silicon polymer mold , if it is hard enough can produce 1000 parts. But final part will be little bit smaller than the original .
Polymer streches , thats why they use injection molding. Tons of pressure
Best way to invest in small lathe.
Its 6 AM , I did not sleep yet ,..