Okay then, does the cat have to physically look like what the car came with or can it be just a generic specimen from a speed shop or a corpse from a salvage yard? I used to run D-100 p/u cats on my old 78. Totally burnt out and no recycle value to them but it satisfied the legal beagles. Blew at least one of them off when it clogged up solid and the motor retaliated. STill have that motor; car is long gone and turned into a toyota that has probably been recycled now as well. Don't know what they turned it into. LOL. Oh, and does the cat's attachment have to be a solid connection like a weld or can it be a couple of muffler clamps or a pair of Vibrant sleeve clamps or similar? Asking this because, once the visual is done and you have escaped, you are likely going to want to dispose of that catalytic nuisance; just don't throw it out. Keep the insert stashed for the next time the inspectors come a-snooping.
Nick