Unfortunately manufacture dates were kept by the floor foreman so that the piece workers that assembled them could get paid. Most of those records are either lost or yet to be discovered. The senior Senator of the SWCA from CA has some IIRC and shares the information from time to time. The shipping department did keep serial number records as a means of inventory control and accounting and those records are what are used for shipping date requests in the SWCA request forum and by the Historian/s when a factory letter is requested.
Multiple examples have been discovered where a gun for whatever reason shipped way out of "normal" sequence and can show a ship date years or even decades away from others with near serial numbers.
Sometimes guns were given to gun magazine writers to examine and write about and returned years later and eventually released to the public. Sometimes they landed in the factory collection or with a family member and again returned at a later date. The other main cause of ship date differences was the fact that guns were stored in a vault on shelves with no concern for serial number order. Newer models were placed in front of older ones and therefore were grabbed first while the older inventory sat around. The shipping department was only concerned with filling an order in exchange for payment and there was no concern as to what serial number was stamped on the gun. As long as a record was maintained showing inventory disposition, everyone was happy.
The company was concerned with making money (and they made a boatload) not so much having some order to serial numbers. That is something only collectors are concerned about.
