Here's a pic of the test fit piece being sent to me to confirm everything mates up properly.
DKF had the test piece polished so that you can see what you'll be getting.
The CAT/resonator piece is just that...
It is a trial piece to test O2 location & a resonator body was used rather than wasting a good CAT for test purposes.
I have some larger pics but they will have to wait until I get home to reduce the file size for uploading.