I had the same problem on my 64. The vent window seals were very tight at the front, but I could close them by pushing in on the glass at the rear of the window, rather than trying to PULL them shut with the inside handle. There was still a small area at the bottom that did not seal. I cleaned the rubber with thinner, put grease on the chrome at the bottom of the window (to prevent sticking) and applied some Black RTV to the rubber. I then closed and latched the window and left it overnight. I opened the window next day and trimmed the excess RTV, and now have a good seal. I still close and open the window by pressing on the outside, but that really is not a problem. Hope this helps.