Has any one ever used tooling wax sheets to get panel lines. It comes in various thicknesses and shapes with just a little practice to about any shape you wish. I have used them for depressed lettering, and to get a 12" clean edge on a deck mold for a 65" power boat to end the non-skid pattern. It is a one shot thing on the mold as the wax sometimes stays in the mold. but you could even press in rivet lines. I am thinking of doing this on my Goshawk. Make the plug 1/8" shy and overlasy the tooling wax sheet, put in rivet lines panel breaks and the like and then, carefully make a left and right mold of the paneled areas of the fuselage, turtle back and bottom panels. CST sells .007, .015, .02 and .062 thicknes.
http://www.cstsales.com/mold_making_supplies.html