Here's my research on the topic. It even includes part numbers:
viewtopic.php?f=3&t=10512&p=159666&hilit=kawasaki#p159666I spent several months looking for them commercially. CMSNL doesn't have any in stock, and can not get anymore from their suppliers. I've registered with them and have had many emails back and forth. The only way to buy them, is used at auction or through an internet board. I was thinking of doing a small production run making them out of aluminum, but I don't want to step on any toes seeing how Mastuo makes resin ones already.