I gutted a 2.5" catback with an N1 muffler a long time ago and its been sitting in my garage ever since. I won't lie, it's not the best setup ever, but its yours for $40 if you can come pick it up from my place.

I basically cut it off behind the flange for the cat, so you'll have to weld a section of pipe w/ a flange on it. No problem for an exhaust shop. It's all one piece, but I can cut it into sections if you want. The muffler was dragged so its scratched on the bottom and there's some corrosion on it, but it still looks great from above. The hanger on the muffler itself broke off too.

Send me a PM if you're interested

Here's a couple pics.