Thanks everyone, the story had a happy ending though.
I was lucky to get robbed by stupid thieves with a conscience. Just as stupid as me, I guess.
The cat is fine. Attached is the photo of the stolen "cat". They actually stole the front exhaust box/muffler part , thinking it was the cat. When they figured out their mistake, and that what they had was worthless, they put the the part back in the area where my car was parked, and I found it today. It was in perfect display, wiped clean.
Currently I'm at a specialized garage getting it welded for a fraction of the cost of a new cat (even an aftermarket one).
Oh, and I'm getting a garage.