Yes it is an ifor Williams 105, it has the roller shutter door, we looked at the drop down door but decided on the roller shutter due to parking etc.
The sides of the trailer have metal securing strips(the type found in some lorrys)
I screwed timber battens in to them then affixed plywood to them, making a very strong wooden box within a fibreglass box
I can report that after 6 weeks of continuous bouncing and abusing the shelves etc are still exactly the same as when fitted, these Festool drawers are great