This is a simple handbrake I designed it requires a couple specific parts but if you do not have them (as I would expect) then you can modify them I supplied the F3D archive if you wish to use fusion.

current base design just screws into desk if you wish you could change how it is designed.

NOTE: you will need a way to make it work as a HID device - i used a macropad I had built and soldered the microswitch to where the switch connects on the PCB.

Parts:
"KR50/1" micro switches scavenged from a dead parkside bandsaw - photo attached
the metal bar from a amazon broken quick-clamp - photo attached
7 x m3x20 bolts and nuts
2 x m4 nuts
m4 bolt
m6x30 bolt and nut
some elastic bands to pull the lever back

The handle used was a model from GrabCad that I removed the screw thread and cut a channel through for the bar to fit into.
Model I used: https://grabcad.com/library/gear-knob-v1-spc-spc-1

If you think this is too much, fair enough , it is not easy as you would have to adjust all the prints to work for the parts you would use. and that is ignoring the fact you need some sort of macro pad or something to solder wires to so it can work.
but if you do want to build it remix this and share it to the world! or sell it if you wish.

Good luck and have a good day!