Good luck with that, look at Rolex, Gucci, LV bags...
It sucks to be copied especially when you work hard to come up with something original...
Unfortunately a small alteration in the design can make the case go to waste.

I agree that those cartridges are a bit expensive but that doesn't give the right to anyone to snatch off a creation that probably took hours of engineering and lots of money.
The T-Teck Cartridge has a different design and it's a one piece Unlike the Hawk...

It's a fine line...i you think about it all coil machines are almost identical to the O'Reilly's version...should be all sued...Maybe