Power Mac G4 cube retrofit - Orange Pi 5 Plus

This is a refresh of my G4 cube retrofit kit. Version 4 takes us back to ARM with the Orange Pi 5 Plus. The only change from the Zimaboard version was to the PCB plate to accommodate a different SBC. The other parts are just included here for the sake of completeness.

edit: Added "levers r3". I've found wires going past the levers can push hard enough on them to unlatch the mechanism and risk the skeleton falling out of the model. These new levers are moved off toward the inside of the skeleton to make room on the outer edge of the skeleton for any cables. I've also tightened the grip they have on the collars at the bottom of the skeleton. These upgraded levers are compatible with v2 and v3 of this project as well.