Jeff,
Do you have any 12/64 SJ images of trunk lid weatherstrip you can share? Looking for typical application of the yellow weatherstrip; brush strokes, sloppy or neat, etc. Thanks.
OK here is one from a few weeks before your but IMHO typical of the factory and period
Adhesive applied with the brush so it seems that you can always find at least a section where the brush/adhesive was applied to a section where the weatherstrip would not cover.
In the example below it was on the drivers side upper inside as indicated by the green arrow. If you notice the worker, on this car, did not place the weather strip tight against the lip as he should have in that area but even if he had the weatherstrip would have not covered all the adhesive applied
While at it the orange arrow indicates where the two ends of the weatherstrip meet on this car. Typical IMHO