Mike, I dont have that equipment, nor the expertise to use them, but i have used a microscope before to examine dies. You can probably just use a regular microscope for this scale, and The LED even has a clear lens to see right into it. I still wont be bothering to do that. Instead I built the thing, and have been running it as a test to see how long it will take to fail, and it has shown no signs of failure yet. Its been months with no sign of dimming, no smoke... it just keeps working.
Dhenry, thats some sound theorizing. I remember before when you mentioned batteries having an internal resistance, and shift registers possibly working as current limiting devices. Your theories have merit, but I have no idea how to test the theory.
its also possible that parts are under rated or materials or manufacturing have changed, and made improvements that never got re-factored in or tested.