Don:
You can determine the date of production by looking at your data plate located on the "A" pillar of the drivers' side door. Look at the second line :
01-7-1B6K-???-x
Where the question marks are is the production date of your car could be, as an example, 809, which would indicate August 9, 1957. So look at your data plate to find the production date. Hope this helps. John