Hello from California!
Good luck with this. You will probably get more help if you post this in another area like "exterior" or general mopar tech".I am in a jamb. I need some help to understand how the convertible top (plastic window) and top connects to the rear bow at the trunk. My car didn't have any bow so trying to figure it out. Can you send photos of your car showing how the rear bow is situation in the back, and most importantly, in the corners of the back side. I tried taking the Belvedere and modifying but I get creases due to the area near the corners that stick forward about 1-2 inches creating a bow.
Help is greatly appreciated.