I have a 72 350Sl (more correctly called a 450SL). I take a stab at this.
I understand there are two style rotors for our year car. The rotor you showed in the photo is for engines 005019-030108. Are you sure you have the correct rotor for your car? The other rotor which is the one in my car (see photo) is dead simple, no springs or other gadgetry.
1982 300D Turbo