We are trying to organise the ladder racks on the new Transit Custom. The rear rack has (and needs) a roller to allow the ladders to be held clear of the paintwork. Standard fit puts the roller at the top of the tailgate door and obstructs it. I have considered a number of ideas including a hinged roller, but the final solution is a sliding roller. Cutting it down was another option but then the ladder would hit the bodywork. I now need a couple of lengths of square section metal that another smaller section can slide inside of, something like an engine crane boom, with the same pin and R clip idea for setting in or out. Can someone suggest a couple of square section sizes that would do that nicely please? I anticipate the inner being something like a 1" square or maybe slightly larger. The roller is an 8mm bolt in each end, so that is the only critical dimension.