I would largely guess quality control, part staging, and maybe even revision control to some degree. These were small batch cars with only a few thousand parts build, maybe even only a few hundred if you go by revision level of each part. For the most part you expect any part to fit any year of the same respective design, but say you had something like a Mamba with unique trim or even just two different colors that were similar for exterior panels. The numbers might just help to keep track of which part goes on which car. Do any of your numbers remotely resemble any portion of your VIN maybe? Might also be a build/production order number, as the cars weren't always built in sequential VIN order.
Kind of like all the paint marks on classic cars that people look for at judging events. I know you can still see the odd bit of color on some bolt heads of my 71 Vette for the original pens, but they are pretty few and far between on mine as it's nowhere near a concourse style car, just a driver.
) I'm surprised there is no record of why. Quality control? Build stage sign-off? Or did they just know each build was special and signed each car?
