Depends on how bent. It's going to be pretty hard to straighten the rolled sections or remove dents from them without pulling the ends to get inside. Good used tailgates are hard to find. I looked in lots of places and wound up buying a new one from Mar-K on a visit down that way. Everywhere I looked I found trashed tailgates.
I cut the center section out of my old one and will make a wall hanging out of it someday.
Post your wants for a used one in the Swap Meet section.