My guess is Bassani. My last Cobra had Bassani mid lengths through a Bassani o/r x and 2 chamber flows. It was pretty loud... When I had the hi flow cats welded back on for smog, it wasn't too much quieter. Felt about as fast too.
I believe BBK makes a catted H, as well as MRT. I went with the Magnaflow cats for cost, $120 for the set, plus I already had the o/r H and could weld them on myself (not very well though) !
this car has had 2 pair (1pair original, 1 pair replacement) of the Bassani cats before I got the car and then a set of Jeg's cats were installed and showed better results than the Bassani. The cats were replaced just to rule out clogs or restrictive flow.