I recently acquired a G1 getaway Powermaster, but it has some yellowing problems. Does anyone know how to restore or repair this?

For the chrome parts that are yellowing, I tried using a silver marker to cover it up. It looked great for a while... then it faded away again showing the yellow.

 

I'm still looking for other solutions.

Actually i have no problems with the chromeon Getaway, it's the White which has yellowed. Someone told me to use nail enamel remover but that might damage the paint. Isn't it?

One suggestion I heard was using very find sandpaper., (2000 grit or finer)

Check your local hobby shop, I hear of a plastic polish that would work like compounding your car's paint (stripping away the discolored layer and getting down to a layer thats untainted). Sandpaper would work, but would leave the plastic rough, not smooth and shiny.