Vewlix L Brighten White Plastic

[tonyt76]

Hey guys, my Vewlix L plastics have aged and im looking to make them bright white again. Have any of you done this successfully?

 

[rewrite]

Try cleaning it. You'll likely find a fairly solid layer of that yellow is just caked on smoke/etc. Isopropyl alcohol (99%), automotive paper towels (the blue ones), and a lot of elbow grease will get rid of a lot more than you'd expect.