That's not correct. Orders were placed sometimes months in advance.
The tag was made for the build, not for the order.
'Months in advance' may be true for larger volume orders, or for dealers orders leading into a new model year, but in cases of a 'customer order' (which receives higher priority for build scheduling), it is generally 2-4 weeks. I 'special ordered' a handful of cars (Chevrolet and Chrysler) during the early 70's, and the fastest a car came in was 2-3 weeks, and the longest was around 4 weeks prior to the cars' build. I know from my own engirneering/manufacturing background (not the automobile industry), that when an order was received, it was 'estimated' when the order could be filled (for feedback to the customer). Since all the other information on the cowl tag (model/options/etc) is KNOWN, or generated (bdy nbr), at the time of order acceptance I'm curious just exactly how long after order acceptance did it take Chevrolet to provide the information to Fisher and and when did Fisher 'fix' the data that would go on the cowl tag? I'd think this would happen in a few days to a week at most.
The fact that some cars cowl tag date and actual build date differ significantly suggests that there was sufficient time between the "cowl tag data generation" (that could be well before the cowl tag actually being made) that temporary unforeseen parts shortages etc could affect the time difference. If the cowl tag data (production week) was generated at the time the car was actually beginning the build, then we should not be seeing the significant difference in the dates as we do. We've already been informed by JohnZ and others that once the body began the process, hardly nothing affected the build sequence, and the production rate was 'fixed'...