Maybe DIY. Some duo modders used to make molds of old parts to recreate them with transparent plastics. I've heard various success and failure stories so I don't know if it could be used for your project. Anyways a couple links:

http://www.powerbook.org/duo-zone-e/danger/clear-parts.html
http://mywebpages.comcast.net/gionpeters/hhhh/resin.htm

If you can create your won mold, Tap plastic sells the plastic resins you would need. Not exactly cheap - it looks like you can get a gallon of resin and the catalyst for about $50 online. But it would probably be cheaper than getting a plastic molding company to do it.