I have observed that, below sn 200K, Parker 16's are about half 0 frame and half 1 frame. After 200K, all I recall are on 1 frames. What is the latest folks here have observed?
The latest I recall is 183238 . The next question is why and my theory is they determined the 0 frame was a bit small and they got better at making 1 frames lighter, but who knows.
And since everyone loves pictures . . . Here is one from the 150K sn range
