I was speaking with a friend regarding the dim lighting on my instrument cluster. Besides recommending cleaning the conducting points, he asked me if the white bezel had "yellowed", and said that if it had, then to paint the interior of the bezel gloss white. It made sense. So as I'm replacing the standard instrument set with the tic-toc set, I painted the interior of the bezel gloss white and it really does make a difference in the brightness.

I removed all of the instruments with just a few screws and nuts. I realized that the green light bulb covers had a very small weld and could not be removed, so I taped them to avoid over spray.

It's such a simple thing to do that I thought I'd pass it along. Don't expect it to be as bright as a modern day car, but it is an improvement from what I had.

The pic below shows the difference from the original surface and the painted surface. Hope that this helps you too.