I remember a post from Marko/MPU over at the old place, where he vacuum-molded a Triumph-style pickup cover out of PG material for a Les Paul Signature bass project. It came out nice! He had made a mold from wood, interfaced it with his shop vac, drilled holes in the appropriate spots for suction, and plopped the thing into an oven with PG material laid over the top of it. I remember there were pics of his whole process, but I can't find them anywhere. Just FYI, and maybe you can contact him via TB for insights.
That said, I like it without the 'guard! Reminds me a bit of those Acoustic Black Widows