I have a book on Norse Magic, and I looked up these symbols. They are not Norse symbols. As Carmel HP said, they are somewhat of a play on that symbol. The book also says that their symbol (which points straight up and down, no angle) is the Norse "s".
Point taken. It's a natural thing to play on alphabetical symbols. How many variations do we have of our current S, or any other letter at that? Did the Nazis borrow the runes? You can bet they did.