If you are looking for the SON (Shipping Order Number), the first four numbers of which is the Scheduled Build Date, tha information is on the body tag under the hood, right below "SON" ,
For your VIN -
4235 129509
4 - Car Line - Dodge Six
2 - Series - 440
3 - Model Year - 1963
5 - Assembly Plant - Los Angeles
129509 - 29,509th 1963 model car off the LA assembly line. Your 1963 Dodge 440 is one of 29,727 1963 Dodges built at LA.
If you want more information on what is on your car and cannot find a copy of the broadcast sheet, you can order a copy of the build record for your car from FCHS. It is an IBM car with all the info on the broadcast sheet on one small card.
Bill
Vancouver, BC