I just skimmed over the thread.
What I sugest in doing is, When making the Positive part of the mold is to rough shape it as close to what you want and then use modeling clay (petrolium based), shape it to how you want and then heat it up with a heat gun or blow dryer to has the grease from it come out, this will help even the shape a little and will help the clay to be removed from the negative.
when making a negatve to be used as a mold, before you start building the negative, lay a layer of Alginate (dentists use this to make molds of your teeth) over the positive and then build the negative off of that (A lot easier to separate the 2). then when making the actual dash, lay a THIN coat of vasilene over the Alginate and use a heat gun or a blow dryer to even the coat and start laying the CF or fiberglass. Maks the end product more finished and if there are blemishes, they are usually easy to wet sand and buff out.