Post-Script: Double points get assigned to whomever can identify the source of the artwork on focus at the view screen shown in the second photo. I was using the binocular lens on the front of the box, shown in the top photo.
Here's a photo of the red-LED circuit, with plastic diffuser. As you can see, the interior of the box in the background (not yet painted black) is nicely illuminated:
I thought, for the sake of completeness and those darkroom photo nerds out there, I'd post results of my red light + photo paper fog tests.
Starting in the upper left corner going clockwise:
Red RubyLith window + Red 25A eyepiece filter both opened, 2 minutes exposure (intense fogging);
With eyepiece closed, 2 minutes exposure (still intense fogging from RubyLith film);
Red 25A eyepiece filter open, RubyLith window closed, 2 minutes exposure (still intense fogging);
With eyepiece closed and RubyLith window stopped down to 1/4" hole, 20 seconds exposure (still slight fogging);
5-watt red-LED directly above paper, 2 minutes exposure (slight fogging);
5-watt red-LED filtered through plastic diffuser, 2 minutes exposure (NO FOGGING-YAY!!)
Typecast via Smith-Corona Silent; photos via Lumix G5.