Yes they can be restored with a very delicate touch.
The paint cannot be removed with anything that is too aggressive. It will craze the plastic which must stay smooth and clear. They are painted from behind , then a gray paint over the last color so it is opaque.
I use thin viscosity super glue to fill cracks and scratches. Build it up in layers then sand smooth going grit to grit through 1500 or greater wet dry sandpaper, then buff out with McGuire’s Polish…working from aggressive to fine usually by hand with a microfiber towel.
I use either testers enamel or sometimes a product for RC race cars that is Alclad Lacquer from the hobby store if the color is available. RC car bodied tend to be painted inside out like the emblems. Use an airbrush for this. The Lacquer or paint may be translucent when done, so that is where the gray back painting is important.
Hope this helps!
Greg
