MC, is there a way to physically tell the difference between the K0 - K2 and K3 - Kx forks externally?
The K0 would have smaller fork legs at the top where the seal goes as the seal was smaller. At mid K1 I think the seal was enlarged, making the tops of the legs larger, so that clue goes away.
The fenders changed. I think the brake caliper changed shape at K3 from the "C" bracket to the "T" bracket. But I don't have the details memorized. However posting a pic of what you have should get an ID from the forums, quickly.