There is a product made by Novus for this specific purpose. Their website link:
> Restore Faded Plastic, Plastic Restorer | NOVUS Plastic Polish <
From my experience (I owned a plastics fabrication company). Restoring plastics is not an easy job. We kept Novus around, but it only worked on very superficial scratches.
One other thing... acrylic plexiglas can craze. It is that crazing which makes it virtually impossible to restore. Get a magnifying glass or thick glasses and look carefully at the surface. If you see very very fine cracks under the surface of the plastic then the restoring the wing is a lost cause.
The most common reason crazing occurs on plexiglas acrylic is because it was cleaned with windex or some other ammonia-containing liquid.
It is possible to make a new piece. If you want to know how to do that I will tell you. Just let me know. It may be a project you would enjoy doing. In truth, the time and effort it will take you may not compare with just buying a new wing.