[Snowtractor]

Never caught a fish with that bait before...seriously Jim are you looking for a manufacturer or a product for rubber moulds etC. .If you are refering to your handgrips posting, I would wager that they were injection moulded not cast, though I could be wrong. YOu get a much more dense and durable product that way and , generally speaking faster production with less air intrusion. Silicon makes a good mould and will conform to the shape of the originals well, if you aren't machining a mould. Make sure you use a mould release though. There is also rock and roll rotational moulding using an oven or flame moulding. I suspect you want to pour your rubber into a mould copied from your original , if so you should have a vacuum chamber to remove all the air out of the liquid rubber or each bubble will likely be a hole. As for products they may be listed under rubber in the yellowpages however if not they will likely be under plastics. Any decent supplier will help as to figuring out a product that best suits your application.
Sean