Animation cel oxidation

Hi,
I purchased some very expensive Transformer cels from the 1986 animated movie, unfortunately they have yellow oxidation on animation cels. Has anyone had any luck restoring this type of damage?? You can see it on the left hand side of this cel.

http://guardians.rubberslug.com/gallery/inv_info.asp?ItemID=287334

Thanks
Frank

I'd try this company srlabs they are great at restoration http://www.srlabs.com/our-services/restoration.html