Cant wait to see the final result was there any corrosion ????

yep sure was.
I have some photos but i will post them after the corrosion has been removed so i can put the before and after photos.

some of the inserts under the mylar had some brown on them, looks like it has been burnt, i am assuming the adheasive on the mylar has gone brown, there also was a bubble in 1 of the pieces of mylar.