Bob:
I had three vintage Mustangs over the years. One of the Mustang owner's challenges was to find the "Build Sheet" for his car. Ford had destroyed all the option information for vintage Mustangs so Ford could not tell you what options came with a specific car. The Build Sheet had a lot of information. The Sheet traveled with the car down the assembly line (at Metuchen NJ, Dearborn MI, or the California plant.)
The Sheet was left someplace in the car under some part. Sheets have been found under the carpeting, inside the roof headliner, and in other odd places.
Not sure about Mercedes but I've never heard of a similar build sheet being used. I seem to recall reading that as orders came in from dealers they were punched and coded into the data cards, VIN's were assigned at that early stage. The data cards specified the options, the market area (such as USA) and a lot more, as you all know.
The Data Cards traveled with the cars down the produstion line. (I had the honor of an escorted Stuttgart tour to watch cars being built, including W113's.)
Maybe Klaus D can tell us more.
A few years ago, I was in contact wih the daugher of a retired MB production line worker but she said he did not want to talk about his old work.
Richard M, NYC