Thanks for the correction Tex ! you would think they would be easier to find.
Kawasaki did not provide Partzilla, CMSNL and the others with 100% accurate parts info, but it is correct, probably 99.9%.
It does seem odd that they are so hard to find, but maybe that is an unrealistic expectation for a plastic part that has been out of production for decades. Also, a lot of these bikes that ended up in scrapyards have been crushed for scrap over the years. I think it is the same pattern as often seen with collector cars. There are often decades after the end of the model’s production that they are just an old, used machine with little value. During this time, many get parted out or scrapped as they are to. Low-valued to be rescued. Some years later, older folks with some discretionary income, who remember the vehicle with fond nostalgia, begin restoring them, driving up interest and value, especially for esoteric parts. In rare cases, aftermarket companies will step in where it makes financial sense. For instance, the price of 1967-68 Mustang fastbacks has left the stratosphere, and if you have a viable vin, you can build an entire car from catalogue parts, including the body shell.
I doubt if that will ever happen with our beloved KZs, because Kawasaki produced only a tiny fraction of any given model compared to the average collector car.
Still, there are bound to be a few more air filter boxes hiding out there somewhere.