I purchased an older, never flown Super Chipmunk. The covering on the wings has some wrinkles and I tried to get it out with the heat gun and the iron. Doesn't seem to work. Looks like a foam sheeted wing. Any ideas. I can leave it like it is, but, I would like the covering to be as wrinkle free as possible. Here are some pictures of it. I'm sure it won't hurt anything, but I know they are there.