Hi James,
That's very interesting. Just the kind of detail I will get obsessed over. My car will never be competed at the kind of meet or show where that would matter but I just enjoy those kind of details and I enjoy putting them on my car. I am still surprised no one has a recommendation for the best repop louvers. Several places advertise that they have top quality examples (HBC, Tamaraz, Rick's, Camaro Central, etc.). I suspect they may all be from the same supplier. So, I may take a chance and order another set and see if they are any better than the ones I have.
Allen