I started the project by carefully gutting the viewers and bagging the parts based on their serial numbers for future reference. I then did some soldering and fitting of a 2.8" PiTFT screen, Pi Zero, four port USB hub, USB mini speaker, USB game controller, power supply using the vintage power switch on the back, and finally, a 32GB RetroPie game collection with a Star Wars theme including soundtracks playing in the backfround while searching through the game menu (courtesy of CoinJunkie and ArcadePunks).
These viewers look big enough for lots of internal parts, but that is deceiving. One third of the space is required for focal distance to magnify the image through the glass magnifier. Most of them are built out of die cast metal, so they feel nice to the touch.
Obi-Wan Kenobi would have said - "Your fathers's RetroPie. This is the gaming system of a Jedi Knight. Not as clumsy or random as a plastic case. An elegant system, for a more civilized age."