I think you would be better off removing the entire exhaust system to make any repairs. The 1200 exhaust systems ofen rust in the area you speak of. That would be the end of the header pipe and the header pipe recepticle portion of the main system. The also rust along the seam in the main body.The screws that hold the chrome cover on are difficult to remove even with the system off. You will probably need an impact screwdriver and plenty of penetrating fluid. If the header pipe and area are rusty you can have new adapters made and welded into place. If you take it apart you should be able to reuse the chrome clamps but you will need new gaskets. nine times out of ten the exhaust systems are worse than they appear from the outside.......you might be able to make a temporary repair without removing the entire system but you will most likely have to go at it again in the near future....