'75 duster windshield gasket

I gotta wonder if there was a change in the pinch weld area (fence) at a year model or if vynil top equiped is a factor. The vynil top material went in under the molding clips thus pushing the molding toward the glass. Don't sound like a big difference anywhere except at the tops seam folds.
I've got 2 OEM rear gaskets for 68 and 69 notchback cudas. The 68 was vynil top equiped and both its gaskets are interlocking one piece type.
The 69 gasket has a round rubber lock cord where there was no vynil top.
Not an answer , just clues. Good luck