I installed a 7 piece kit in my 65 a few years ago. The mistakes I made were, one, not pre-fitting before painting, as I remember the lower corners were not quite correct angle and needed some heat to get them fitted. second, the rear window sealer was soft and they had used to much and it kept the trim from setting correctly in place. Maybe I should have either tried to trim the sealer, but that is kinda difficult, or do the trim when the rear window was out and then set the window. I have ran into this sealer problem and interior trim on several of my GM cars, with both type of glass ribbon an sealers.