Monitor 75mm to 100mm adapter
Tested, works great.
See photo of it holding the monitor safely.
You will need m4 threaded screws and m4 nuts.
The nut position is press fit, use pliers to press the nut into place.
This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/ijTEk1ruOPr