There was no exact amount of glue that was used... some have more than others. The car you posted still has the package shelf flap covering alot of the glue...if the flap was pulled up you'd likely find a very similar residue of glue, maybe not "quite" as much, but very similar. I don't see why anyone would assume every car had the exact same amount of glue or the exact same style of hand written X codes.
All these things were just hastily and sloppily applied by some line worker in about 2 seconds without concern over who would be scrutinizing their work 35 years later.