Well that is embarrassing, I made a huge error on the positioning of the focus knobs of the microscope so the models I made yesterday are invalid. PSA: Measure twice! Or at least take a look at the model and see if it makes sense!
I did print the bracket anyhow to see whether the concept works, which it does:
Will measure the force needed to engage the wheel in order to select the right size extension spring, and of course heavily modify the stepper motor mount in order to work with the microscope.