Lots of great progress on my new annunciator panel design. I cut and drilled a piece of 0.063" aluminum as a prototype mounting plate for the LED light assemblies, including holes at the corners for the #6 screws that will attach it to the instrument panel. If this layout scheme turns out to be an aesthetic success, I'll cut the final version with a CNC mill so all the holes are perfectly in line.
I also created the printed legends that will fit inside the light assemblies. I used Avery Clear labels, printed in Bold 10pt "Franklin Gothic Demi" font. (I originally tried "Arial Narrow," which fits and looks nicer, but the weight of the characters was a bit weak, which made the labels a bit harder to read.)
I also researched ways to dim the entire annunciator panel using a potentiometer on the ground side of the lights. I'll test this method sometime soon.