I guess it depends on how its bent. Mine were more dinged and dented rather then bent. I just hammered out the dents making some anvils out of hard maple to match the contour. Then sanded it smooth using a block of wood starting at 120 grit up to 2000 grit. Then buffed and polished. They didn't come out perfect. You can still see waves if you look from the right angle. My drip rail moldings were more then I could handle so I have some one else working on them. Its just taking him a really long time.
If its a soft bend maybe you could get away without polishing by applying pressure in the right spots with some thing soft but if you start hitting it it will scratch and dent.