Here is one to show with and without light exposure. I removed a peeling pick guard when that 410 was about age 16, since the corners were lifting. You can see where the more transparent portions of the tortoiseshell pick guard left "freckles". I tried masking it off and it spent about 35-40 hours in direct sunlight, but the light and dark portions never really blended back together. Maybe a couple hundred hours with a UV lamp might have fixed it, but that was beyond my patience level for that project.
In the end, I just put on a plain black pick guard in the standard Taylor shape.