I made 4 of these up for my 76 and lost one off the rear wheel a few years back...When I bought these the plastic octagonal piece was readily available, I should have bought a dozen! they're made of good heavy plastic w/4 big friction ear/clips snapped in place tightly...NOW I CAN'T FIND ANY!
Anyone know where I can source these? I'm tired of looking...I had the center logo gel Porsche logo crest pieces made by an outfit in Thailand if I remember right..