Just another option to fixing yellowed plastic. I tried just straight up bleach on a junker jetfire I got a while back. The results were pretty good, but I had a problem with keeping up with the bleach because it readily turns back into water. So I can't recommend a time frame other than to pour some bleach in a bottle with your parts and seal it up, then check on it every once in a while. I haven't used bleche-white yet, but I from other posts I read, I think the bleche-white would work better. I should pick some up and try it on the other wing to see a comparison. Here are my results. Both wings had the same amount of yellowing. One was bleached, the other wasn't. If you look at the picture of the back of the wing, you can see little white dots. I'm not sure what caused this, but they were not there before. I have not seen any degreadation of the plastic, except that it has lost its shine. This could probably be fixed by buffing the plastic or a clear coat of poly.