What exactly is "profile"? Sanding all the rust pits out to get a smooth surface?The prep work would be the same as any new pipe would be. Sand blast with the proper media and profile and shoot the ceramic. It is more worth than spending big money to replace them. Your last few posts have made me lose any confidence in what you say on the subjects, you seem to be greatly misinformed.
And I don't know who you're buying "stainless steel" from but in 25 years of designing exhaust systems for OEM automotive companies I've never seen any grade of stainless that gets red rust on it. Kinda defeats the purpose of using stainless, don't you think? But then we wouldn't waste time or money on a material that shitty anyway so I guess it could exist.
But thanks for straightening me out in you oh so holier than thou way.