Note the West German spec, some of them detuned and they had their own flags on the badges. also seen on the W German spec GPz .
I think in the early 80's the motorcycle industry was acutely aware of impending legislation regarding power outputs and noise levels, particularly from Germany so kawasaki were jumping through hoops trying to keep them happy.
1980 Gpz550 D1, 1981 GPz550 D1. 1982 GPz750R1. 1983 z1000R R2. all four aces