There are 2 styles, one for the outer chrome pieces and one for the stainless center strip. The ones in the middle have raised tabs so that tightening the studs will not cause a dip, bend in the stainless. In 67, they went to 2 pieces, both stainless, which if I remember right have the reinforcements made into the moldings. 68 went to no boot snaps, with slide in studs that required nuts to be attached from underneath. Much cleaner look than earlier cars.
The assembly manual shows different numbers for center and outer clips for 65-66.