Well, my 30 years in the body business might help. What's happened is the color has been bleached out by the sun, even though it's clear coated. Kinda like the reason plants grow in a green house. The suns UV rays still affect the pigments in the paint, and with orange being a shade of red and reds not being super UV resistant, the color gets bleached out. Since the stripes hid the color from the sun, it didn't get bleached out like the non bonnet striped area, so basically it was still new color under there. I don't think you're gonna bring any color back to that area. More stripes might be the only answer short of a repaint. Though DuPont matches hot orange nicely.
As for the Celica, Toyota didn't clear coat their red until the late 90's, though they should have much earlier. They'd start out red then fade to a nice lipstick pick! But with no clear, you could buff through the fade and expose new paint and start all over again.