As said before, plastic molds must be polished to a mirror like finish, or it would reflect any imperfections. Even in small production line which i assume you thinking about it would take a lot of time to hand finish every single piece. However hand finish would not be as good as from a good mold. Anyway don't take me a wrong way, I do a lot of things the hard way myself before i learn to make it wright, which most of the time equals that my trying to save the money, costs me twice as much.. if you know what i mean. I do know some small manufacturer in Europe who specializes in plastic mold making. Economy is tough these days and if you have a part drawing i can put you in touch with them for a quote. I am not trying to advertise here or make money of you.
Just suggesting... Best regards Mike