I ended up getting it all together. Turns out I tried to panel mount a switch somewhere stupid, and I'll have to redo some of the case routing, or find smaller slide switches.
Anyway, here's the finished product!
Everything works, although I keep tweaking the screw tensions to try to take pressure off the screen… I'm not sure if it's that specific backlight or what, but I can't get it in there without a significant amount of pressure being on the screen.
Final Specs:
kitsch case with custom paint and custom buttons.
Panel Mount 1/8" Pro-Sound, wired pre-pot.
Nonfinite V3 Ultra white backlight, switched
Diffused white Power LED
Internal PS/2 port, prototype kitsch hardware.
A heart full of love.
RadioShack speaker replacement, OEM hardware failed.
Actually is the game boy I have had since childhood.