My hitch(tow bar) is home made,it like Brians attaches to the centre spring mount,then has an extra support going up to the spare wheel mount,at the back it has a cross member that attaches to the two bumper mounts on the inside of the bumpers,so far we have done about 35000klms towing our 900-1000kg caravan,still have the mechanical brakes on the 33 ,BUT have electric ones on the caravan.
Lawrie