I will be using fiberglass also and once I am satisfied with the finished plug I will try to get a aluminum mold made which will allow me to make a small run of them(the Aurora) with greater consistence . Here are a few shots of how I did the elevon hinges on the Aurora from start to finish the hinge material was a three layer laminate one mylar layer(4/1000 thick)between two layers of ca hinge type material(3/1000 thick) total; thickness 10/1000 or 0.26mm.