Thank you for taking the time to share your feedback regarding the rear window seal (SKU: PCNF451902) for your 1964 Mercury Comet. We're sorry to hear that the part isn't fitting as expected, even after multiple installation attempts. We understand how frustrating that can be, and we appreciate your patience. We did try to reach you by phone but were unable to connect, so we're following up via email to assist you further. To help us investigate and resolve the issue, could you please confirm the following: Is your Mercury Comet a Sedan (4-door) model? Were there any noticeable differences between the original seal and the one received? If possible, could you send us a photo of the part partially installed or side-by-side with the original? Once we have this information, we’ll be better able to determine the next steps, whether that’s confirming fitment, arranging a return, or finding an alternative solution. Looking forward to your reply so we can get this resolved quickly.