Back in 2010 I sold me rear springs to a guy. I just thought they were dead. I added a set with seven leafs. After 10 years of bumping aroung I was able to buy them back. He had kept them in his shop since he bought them.
The date code is 198 4. They were made the 198th day of 1964 so it is probably the correct springs.
I will mount them on my car and hopefully get a better stance on it incl a bump free ride!