Wheel Nut:
Most 4x2 Units have a fixed fifth wheel, its the 6 wheelers that tend to have sliders more
Never come across one of those, had assumed they all had moveable ones. Checked this Renault and its got one, but it is a 6 wheeler and not exactly new.
Don’t suppose they have a garage on site? If so and you take the job, my first port of call would be them to see if there’s a way to extend it. Wondering if its just not unfurling properly due to some overlooked glitch (our DAFs had a problem caused by the belt holder angle).
Aa a side note, never liked Mavis rails as they aren’t great when you’re not tall. Cant get the pressure on the airlines connectors as they are more shoulder height.