Here's the rear cockpit wall:



You'll notice some corrosion on the aluminum. I believe it is limescale. (It was dripped on). So far, I have tried the following:

- dish detergent
- acetone
- white vinegar
- lemon juice

What you see in the photo is after all of those attempts. Got any good ideas on what would remove the discoloration/corrosion? I also tried combining acetone with steel wool...

Thanks for your input!