Optics module length

As it is:
Parfocal Distance: Approx. 45mm
Mechanical Tube Length: Approx. 160mm

It should work fine, if it really has those specs.

I’m not sure what is meant by “common rail distance”?

Do you have a manual microscope you can switch the lens into and see if it focuses? And if it does whether the parfocal distance is 45 when it does?