Hey Ross.
It is a 83 K model. Just arrived from Colarado. The guy that owned it was a Yamaha Factory "B rider" back in 82,83,84 and this was his personal bike. He has completely rebuilt the bike, to exact factory specs, same as his race bike in 83. It has only 4 hours on it since the rebuild, and he said it had cost him plenty of dollars. I virtually stole it from him for $2730 AUS. Just need to get the jetting/carby sorted as it is set for high altitude.
Cheers, Wayne