A broader question is what was the specific purpose of the crayon number if the production number was already stamped on the car? Was it just easier to see for those needing to reference it on the line? Was there some sort of printed manifest they would repeatedly match it up with to tell what options to put on a particular car, and the crayon number was easier to reference? Did one worker read the number to another who scribed it? Or did one person read and remember the stamped number from in the car and go outside to scribe? Maybe he got distracted on occasion and goofed up? Do the mismatched number cars also have mismatched Kardex options as a result? It seems most of the numbers I've seen are in the same handwriting, obviously it was a set process repeated over a long period of time.

Hmmm - is there a German version of Crayola that was used?
The secret # mystery deepens!