KR is the predecessor of SA. That Nakamichi was pretty cool, the idea was to flip the cassette instead of reversing direction so the heads would keep better alignment. A novel idea.
after the first improvement in 1983 or so, it remained quite true to the end. (Color got darker too) So my 1984 tapes bias nearly identically to 1994 tapes. Quite uncanny and I never tried swapping the tapes into the other shell to do if then they’d have the same difference... (probably not)