Here's a list of casters / injection molders that I sent an e-mail to. I will edit this post to update the status of the communication with them. I have plenty more leads to try, but let's see what these turn up first.
Updated 7/1/04 pm

http://www.axcellproducts.com/ - Toms River, NJ
[email protected]
They seem to do the job.

http://www.icmplastics.com/icmweb/molding.htm - Rogers, MN
[email protected]
A HUGE shop, it seems.
7/1/04 - Received reply asking for specific materials info, color matching info, and CADs. Will call re: "um, we don't have that, will you still take the job?"

http://www.polymerconceptsinc.com/ - Randleman, NC
[email protected]
First e-mail to them bounced. Very Microsoft Frontpage template website.
7/1/04 - Received professional reply. Replied with mold and materials specifications (in plain english).

http://www.thomasregister.com/olc/73868952/home.htm - Tact Plastics USA - Shelby, NC
[email protected]
Lists custom color matching, injection molding, manufacturering. Seems good. But no real website or e-mail?

http://www.apogeedesigns.com/ - Baltimore, MD
[email protected]
I think they do molding and casting...
7/1/04 - Received reply. The reqest is being forwarded to their VP of sales. Wait to hear back.

OUT - http://www.zirconplastics.com/index.htm - only do OEM.

http://memphis.rcoeng.com/plastic/
[email protected]
They seem to offer everything, and have a myriad of other services (soft plastic, design, etc).

http://www.precisionpunch.com/webpage.cfm?page_id=1 - Minnetonka, MN
[email protected]
They do liquid polymer casting, but other less pertinant stuff too.

http://www.methodsmanufacturing.com/ - Fox Lake, IL
[email protected]
They seem to offer many types of services. Spreading themselves thin?

http://www.rsalberts.com/index.html - Montoursville, PA
[email protected]
Offers hand casting, injection, liquid resin casting, and more.

http://www.injectedsolutions.com/android_001.htm - Lanesboro, MA
[email protected]
Seems like a small shop with a few machines. But they advertise full project management.
7/1/04 - Received casual reply. Replied with general questions and material specifications (in plain english).

http://www.ramplastic.com/home.htm - Huntley, IL
[email protected]
Injection molding. Mentions knobs and buttons in their list of standard jobs.

(edit: holy crap, the new bbs just converted that all into real url's and mailto:'s. that's niiiiiice.)