I helped out a fellow Kappa owner back in 2011 that was in need of a catalytic converter to pass smog. They planned on using it just to pass smog, then switch back to their aftermarket. Because of this, I felt like being a nice guy and loaning them the spare that I had. I even paid for shipping. It was very clear that I wanted the Cat back once his test had been completed, however I never got a word back. The email address that I had for the guy always kicked my emails back to me and I don't have the forum user name anymore. I know that I am probably screwed (it really doesn't matter, its just I want to not FEEL screwed over). I DO have a picture from an email where he (Carlos) showed me his car... hopefully this guides me in the right direction. He was from Washington if I remember correctly.
I really hope that it was just multiple communication failures and that this either gets resolved, or I just forget about it and go on with my day.