a factory applied finish is likely to be much longer lasting than one you can apply. What you may find, though, is that the gauge of what you have is heavier than many of those you can find. Some of the places that fabricate the things on site have an advantage since they can make the straight pieces, whatever length, all one piece rather than pieceing together 8 or 10' sections you can buy. I'd rather replace than take the time to clean them up, repaint, then reinstall. Some of the brackets are designed for the specific shape, which may be hard to find. Some of the profiles have been around forever, so that may not be an issue...best to check that out before you decide and then can't find what you need to put them back up.