Any special paint such as color or painted hood treatments done after paint , custom colors or corrections would change body destination on the line. When coming into the spray booth you look at the paint code on the body. You grab the hose off the wall that has that code marked by the paint mixer. His Job to mark the hoses 10 per side. The line does not stop for anything.
I was a finish painter on a assembly line. I was painting my side white and Louanne was painting her side red . When I came to the front it was to late. The body after the oven was removed from the line and taken to what they call the change over department where all custom paint was done and repairs. This sometimes held up the Body for days and it would be finished assembled in that department
In this case the body was not used and another body was pulled and would meet up with the drive line and interior much later in the week. Not all bodies were perfect . Quality inspectors would designate the poor quality bodies to low line none special orders. Sometimes some of the flaws would not be seen until during paint or even assembly because of alignment issues. So never go by numbers on any vehicle. If a special order had a issue and it needed to go out. They would grab the next shell that they could use no matter what number was on it. And that bad body would be used on another in the future. Just cover the numbers up.
Oh yeah it was suppose to be white so we couldn't cover the red. We tried but ended up with pink bleed and sags. I saw things that totally changes some of the expert interpretation of production numbers and build dates in the past. So when I here guys talking numbers as if they are the rules from god. These people never had the life on the assembly line. Numbers a lot of time were not a priority. there would always be issues that changed the production order.