i have lots of experience in 'glass, we built the Mach5 from speedracer, and started doing repops of the original Batmobile
i took my original Cricket dash, bogged up the cracks, inserted 3 spray can tops over the passenger side and one top in the bottom corner of the driver's side
coted it in gelcoat, let it dry for a week (longer than required) then waxed the shit outta it. this made the plug.
coated it with gelcoat again, then used the chopgun to lay in the 'glass. In this application, it should have been cloth instead of chop, but since i wasn't paying for any of the materials, and he was spraying chop anyway, it just got done. this made the mold.
then wax the shit outta it again, spray gelcoat, chop (or cloth) run all the air bubbles outta it, and you got a part.
getting it outta the mold was a pain in the ass, and my original dash was destroyed in the process.
i've got guages in the 3 spray can tops and my tach is in the 4th
it's a real pain in the ass for a onetime use, but if your gonna make parts and sell them, go for it
i will post pocs when i get her out here, 3 weeks