I was talking to a guy over at Coast Airbrush and he said that Iwata needles fit in many knockoffs, legal or not. Makes sense since if one is going to copy an airbrush, why not copy the needle?
If brushes are made in China, then there is no patent issue since China doesn't really enforce what little patent laws they have.
But to be 100% sure, I guess one has to try it.
... So who wants to be the brave one?
BTW, the reason I brought up the needle issue is that the needle is the one area where knockoff mfg. aren't able to duplicate. Well they are. But the sensitivity of the needle requires a higher quality control. And quality control is lower on the priority list when it comes to mass manufacturing of knockoffs.