The Supercar Registry - When did the last 57 chevy roll off the line?

I am rebuilding what I believe is the original engine in my nephew's 57 Chevy. He got a great deal on this car from the son of the original owner. Nothing special; just a 4 door sedan. Engine was frozen. However, only one piston was siezed. Had to hammer out number 7. Crank is perfect, so this will take a rebuild very well with an .060 overbore.

Originally PG car and the engine code bears that out) now with a floor shifted 3 speed.

Was told the heads and four barrel intake are from a 58, and the dates confirm that.

Block was cast July 27 of 57 and assembled August 6. Seems awful late for a 57.

Can anyone tell me what date the last 57 rolled off the line? I have not even looked at the car and the trim tag yet, but can get the vin and the trim tag info. Just curious about when the last one was built.