Right, the super-early-build cars got actual hard stainless mouldings around the windshield and backglass. Shortly into production they changed to a mylar-faced plastic lockstrip used on all A-bodies thru '66. Original material not available, but there's a Chev/GMC truck lockstrip that looks reasonably close and works well in new gaskets. It will not quite fit (fractionally too small) in old gaskets.