I'm restoring a T2. I've cleaned all surfaces of the playfield plastics with Novus 1, as well as glass cleaner, and got a lot of the dirt off. However, some of these plastics are supposed to be clear, and there is a yellowing of the plastic that I can't get clear again. I've been told that it's likely nicotine, but I can't get it clean. See photo.
Is there anything or any technique that will get these plastics clear again?