My 65 skylark were the same,front and rear. Purchased them from a local parts store that sells body shop supplies. Napa has them too.
Lay some masking tape around the outer edge of the window, then use a sharpie marker to draw a mark where the center of each clip is located. When you install the trim firmly press down at each mark. I've seen guys pound on the trim with a rubber mallet and dent the trim.