Dart vinyl top install

First attempt didn’t go well. I had to keep the cussing in control as my wife was helping. After getting half the roof laid down and starting on the back I could see the back corner was short on one side. I had no idea how this could happen. It looked like the top was askew somehow even though we lined up the centerlines. I ripped the top off and started over. The Weldwood Landau glue is great as it allowed me to do this. I then cleaned all the glue off of the roof with wax and grease removed and took any lumps off of the vinyl top and started over. I checked the centerline and it looked like the front was out by about 1/4" which didn't explain the back being off so far. I laid it out again and everything looked good this time. The first side went down well but once I got to the other side I ran into problems behind the back window valence. It’s like the piece was 4" too short. There was no way it was going to fit and the shape seemed wrong overall so I made the call and split the back part so I could finish. Now I have to figure out how to make some sort of mod look good. I might call Legendary and see what they say. Did nobody else run into this? If I look at pics of vinyl roofs I see quite a few variations on how the seams on the valence were done.