The tooling broke and all replacements were the second design.
We've discussed this in several different threads.
This is my theory. Factories used the stock on hand. Say you were hit in '69. The dealer would not have the original stamping. They could only get the second design because the first design tooling was gone.
So even in 69 one could get a replacement but not the factory stamping.
Of course if somebody show an nos first stamping my theory is toast.
Cheers!
Nim