Instrument Panel Lights Dim

The tinted diffusers are there for 2 reasons. They spread the light evenly to prevent bright spots and glares just like the lamp shades in your home.
Then the prevent a loose bulb from falling down inside the panel.
While there are 10 or more bulbs in the average panel , less than half are for illumination. All others are for indicaters.
If I pull a panel for any reason I'll replace every bulb while its out.
I solder a jumper on the headlight switch to bypass the dimmer reostat too which sends maximum power to those few illumination bulbs.

a note about the katsup cleaning...sure it works .Texas Pete will too. The problem will come from the salt in those products.