ALL my 56 Ford side stainless was held on by a nut behind the panels or upholstery front fenders included. During painting the fenders were removed and the trim removed then put back on before the fender was attached. There were “twist” lip clamps with a spring on all but the ends of the rear sides and doors; each had a nut. The roof trim was total different. Once attached to the roof the stainless trim snapped on.