Actually, I am thinking of just using this. Its 'fomular metric 50mm thick' made by Owens Corning. Its high density extruded polystyerene 48kg/cu.m and high compressive strength. Like I said, its used for overdeck (roof top) insulation and very often we just put equipment such as air handlers, cooling towers, piping, etc directly on it (when the PCC blocks for those equipments cannot be planned at the design stage. I am in the building services industry). As you can see, I already have the basic shape marked on it. I didnt go for the fancy curves of the original part, choosing to straightline everything. Will ofcourse make a airfoil shape later. In itself this material is hard and doesnt deform easily. To add to that I will apply atleast two coats of fibreglass cloth on top (will build the part slightly smaller than original and then add the cloth on top). Will then add in a couple of CF dowels or one hollow tube (for the wiring) for additional rigidity. For the screw, I will insert a block of birch and then tap in and use a nylon or MS screw as we used to do with wing bolts earlier. Think that should make it strong enough

Ameyam