I screw 4 short pedestals below the M-UMR12.80 linear stage for the HeNe imaging unit, I clamped it with 4 forks on the breadboard to be parallel to the beam.
Since there was not enough space for the forks, I had to move the hole breadboard by a few cm. 
I did the same with the other linear stage UMR12.40 for the 1310nm probe. Since it is imperial, I had to look for a set of 4 imperial screws in ATC.
All the parts I used, I washed them in the ultrasonic bath in ATC. Except for the stages themselves because the bearings have grease, so better not to wash them.