The current plan is to actually get the Raspberry Pi (Video Drive Section) to work on the tricorders original display. I have a 24-pin ribbon extension coming, and a breakout board that can turn the ribbon connections into wires that will attach to the Pi's GPIO. All I need to do is find the last pcb I need: an
Adafruit TPS61169 that can run the backlight on the O.G. display. Im having trouble finding one in-stock up here in Canada

so someone the US find me one and mail it to me! ill pay!
I did order a new display screen + driver board for the trike, hence the 40-pin ribbon... but Im confident I can get the actual tricorder LCD display to work on the Pi. This would be ideal, since swapping the display is a drastic operation no-one will want to do to their trike. this new plan would only require disconnecting the display ribbon, adding the extension ribbon and feeding it down and in behind the moire. Then going from that spot down to the Pi in the lower compartment. Yes I still lose the tricorders original UI, but first-things-first: Getting Star Trek episodes playing on the tricorders display. after that I can start exploring ways to get the Pi and the original UI both working.
As far as new wires - Its just the 24-pin ribbon and the 3 wires for the IR receiver that I need to get out of the hood section (Activities Unit) and down in behind the moire. Totally Do-able!