rust remover & flip kit ??

[sand rocket]

What is the chemical that is being used to remove rust? Have seen some post with somthing from the eastwood company. Anyone know the name of it?

I picked up a flip kit that a friend had laying around. He never used it. Question is, Does the offset hole go to the front of the leaf or the rear? What is the distance for the offset hole that needs to be drilled in the stock spring plate. thanks