What a fantastic post, Casting_Fool. Thanks for all of the information, and for your offer to take on the project.
I have a question, it's been my pet topic in all of these discussions (you might have seen some of my posts on this topic already): What about making buttons which aren't "colored-clear" like Brian's, but which are instead translucent milky white or milky gray, and therefore will diffuse the light better and light up evenly across the surface of the button? I know that Brian experimented with this and didn't have much success. Have you done this sort of thing?
I have a few reasons for wanting this:
1. The original buttons for the player were a shade of medium gray. I think it would be nifty to have buttons which looked similar to the original factory buttons in that respect, yet also glowed when power was applied.
2. I've seen plastic materials used for other types of buttons which allowed for a very "even" light diffusion. For instance, the backlit buttons on a TV remote control (although I realize that's some kind of a silicone rubber rather than a plastic). In these cases, a single LED was enough to light up the entire face of the unit. I'm wondering if the installation of the backlit button hack could be made easier if we didn't have to install as many LEDs.
3. If the buttons were a neutral color (and since we're using white LEDs), then you could change the color of the buttons by putting color over the LEDs instead of needing a whole new button set.