without a broadcast sheet - plant & car model would help to answer the question

Hamtramck assembly line #1: I have info for 929 "SCHEDULED" cars built 2-days early thru 10/7 a week + late.

Lynch Rd. K-frame dates are a great clue, but it appears the same assembly procedures were not used at Hamtramck

Have you found any dated components with October dates that appear original to the car?