Began construction of my scratch-built annunciator panel. Cut both aluminum channels to length (8.25"). Cut nine slots in smaller channel for dividers, then filed and sanded all edges. Measured and cut nine dividers from 0.040 stock. Used hot-glue gun to fasten dividers into slots in small channel. (The hot-glue gun worked OK, but I'll explore other options later.) I cut two large openings in large channel. Began with drilled holes, then enlarged them with larger drill bits, then hacksaw, then files. Finished holes with needle files and sandpaper. (Note: The center two sections are slightly wider than all the others. This is to account for the 3/16" width of the center "post" in the front channel that will separate the two windows.) I also cut a test-piece of thin Lexan sheet for the light cover. The stuff I'm using is very thin, and cracks easily. I might try cutting up a sheet of acetate instead.