Good question - we've discussed this before, I'd like to know as two of my Camaros fall into the "dead" NCRS shipping reports gap in the '69 model year, although I have the MSO for one of them. I'd like to think the paperwork was created when the car was released for shipping to the dealer, which should be within a day (?) of the completed assembly coming off the production line, which would have included the MSO and the shipping document (maybe) at the same time.
I do have an additional MSO/dealer invoice car, my '68 Z: I've never sent for the NCRS report as I have the dealer invoice for the car with options fully listed. If I wasn't so cheap, I could add to the conversation if I could verify the two documents were created at the same time. Hopefully we'll get a definitive answer -
Regards,
Steve