Behold, something stupid:
A Qtronix Scorpius-35 with box jades swapped into it and converted to bluetooth with a stainless steel ball bearing replacing the original plastic trackball. The "Aristotle" switches inside felt terrible, most not even being clicky anymore.
The line of 4 LEDs indicate battery life, controlled by the Aibocn power bank I hacked apart to fit into the case. The left-most metal button is to control the BT-500 adapter I also hacked apart to fit into the case. The two LEDs above it indicate bluetooth status and blink whenever a key is pressed, the trackball is moved, etc. The button to the right of it can be held to turn on a white LED that the power bank meant to be used as a flashlight. I mounted that in a hole I drilled in the front of the case. The white switch is a killswitch for the 3 battery cells I harvested from bad laptop batteries, since the ones that came in the bank were too thick to jam inside the case.
The aforementioned white LED
I also drilled a hole to mount one of those fancy magnetic USB connectors, which can be used both for charging the batteries and for direct input through USB instead of Bluetooth.
Random picture of all of the added guts I slimmed down and crammed onto the top of the case.
PS/2 to USB adapter I wired up to JST connectors. I heat-shrinked the whole adapter and hot glued it under the trackball PCB. Everything else but the batteries is glued to the top of the case.
Random old scavenged laptop battery cells with vaguely correct specifications, which I obviously did the bare minimum of function testing on.