the 'hinge pins' are the 'rods' that hold the 2 sections together and allow them to pivot - the bolts spinning [door side] means the weld nuts there are broken off their attachment point - on the pillar side they're nuts in cages and the cages [heavy sheet metal] rot
you're faced with the usual TF problem, the lower hinge is prone to corrosion from constant moisture accumulation on that mount plate in the door and in the pocket in the pillar - forget hinge pins, get out the welder
Bill
