I would not put it on a trailer, but use shipping containers instead. Shipping containers come in many different qualities, from the standard steel boxes, to (warmth) isolated boxes with windows meant as portable offices. Such containers can also be put on the ground (so easier to enter) and leveled (for machine alignmnent). And as long as you don't need to move them daily, you don't need a truck.
There are also portable calibration labs built into such containers. As far as I know they just rent a truck and a crane whenever the lab needs to be moved. There are some youtube video's about this, I think even Dave EEVblog made a video about such a portable lab.
Such shipping containers can also be extendable. They ship at standard size, but when stationary you can make them a lot wider so you have room to move around your machines. Look a bit around. There are all sorts of (semi-) standard and (half) products you can buy off the shelf.