It works!
Before
The attachment 0511191148 (1920x1440).jpg is no longer available
After
The attachment 0511192113 (1920x1440).jpg is no longer available
Before
The attachment 0511191414 (1920x1440).jpg is no longer available
After
The attachment 0511192106 (1920x1440).jpg is no longer available
It was about 55F to 65F and sunny (not a cloud in the sky) all day, so I figured it'd be perfect for this experiment. These components were out in the sun from about noon until 7PM. I moved them a couple times so that the angle was more direct and so that shadows didn't get in the way as the day went on.
Here is the super technical method I used:
The attachment 0511191214a (1440x1920).jpg is no longer available
Some things changed more than others, and of course some things I forgot to take good "before" pictures of. The old 3-button mouse was very dark on one side, but has since blended out to be much more evenly colored. The front bezel of that AT tower didn't seem much different, but it was incredibly bad. I intend to do this again the next time we actually have sun, but if the forecast is even remotely accurate it could be a while.
All in all, I think this was a success. The old Kensington power switch was so terribly dark before and it is noticeably better. I'm really hoping that another couple of treatments will get it closer to the original beige color of my IBM 5150 and 5153, since that's what I use it for. I will get more pictures of the other items as I do more sun bleaching treatments.
Thank you so much for posting about this! I bought a cheap ozone generator and have been contemplating other (messier, more expensive) methods for a while now, but we just don't have the climate for the ones that require many many hours of intense heat and sunlight. This I can probably do at any time of the year other than the hottest months of summer. 😀
Now for some blitting from the back buffer.