I just became the proud owner of a used WB E-series pipe. As the pipe is used it is dark brown and is rather ugly on my still almost spotless new WR426. Can anyone tell me if the header is made out of stainless steel or if it has a chrome layer. I am asking this since I intent to "polish" the header with sandpaper, to make it shine again. Is this safe? Any other suggestions, also for the muffler. Another question: has the muffler some kind of glaswool filling that likely has to have some maintenance, as the pipe seems quite "used"?