Cleaning "Clear Plastics" - program holders AMI C

I have an AMI C that I want to clean up a little bit.
Most of the plastics are pretty good, but the program holders [108 pn#H205 Title WIndow (front that you view from)] and rear (strip holders)
are yellowed. It does not appear to be nicotine.
Is there a way to clean these up a little bit? I don't need them looking new, just to look like they are fairly clean, but in a machine
being used