This is a little off the subject of this thread, but when I here of old surviving signs I think about the vinyl lettering I did on a 50's style diner on Rt 66 not far from us. They have a 2 to 3 ft. facade around a parking canopy that's made of powder coated aluminum. I lettered the face with black & teal 6 year vinyl. That was 20+ years ago and it's still there. It's got a few weather cracks, but it's not peeling at all. The only thing I can figure is the aluminum is dissipating the heat keeping the vinyl somewhat cooler, even though there's nothing around there to block the sun.