Twisted wings are often said to be warped. When they are covered with Monokote or Ultracote, you can often remove the warp from the wing. It's often fairly easy to do.

You need a covering iron to do it.

Block the wing at the root so it's held solidly. At the tip, twist the wing the opposite to the warp. The covering will wrinkle. While holding the wing so the warp isn't there, use the iron to remove all the wrinkles. When all the wrinkles are gone you can release the wing. The warp just might be gone. If it isn't then repeat the process. Sometimes you have to overtwist.

It's a technique that all of us can learn and most already have.