I have a GK71B with pitted forks, wondering what if any other bike's forks will fit in. Can't find any of the same bike anywhere in NZ for while now...
Hoping maybe the GK71 series at least or perhaps even later models would cross over?

Cheers,

It will depend on what diameter the tube is.
They have tended to get larger with each new model, for example the 73a and bandit4 have 41mm tubes.