I just talked to my old friend that worked on the line and I asked about the spare and the markings. He said the spare was put into the car long before he put the wheels and tires on the car which was near the end of the line. He also said the markings under the deck lid was an inspector at the end of the line that checked the spare,jack, trunk mat and any other related items. The marks all depended on what the inspector wanted to scribble they all did their own thing, The tire was the main thing they noted.
Thanks for reaching out to him. This does tie together many of the comments from the group. Reading your post, it sounds like he was working it the trim section of the line at Lynch Road? I have many questions about the process there.
The comments in the previous "Patik" article on the Super Birds could be unique to that model.
D