The exposure dial is separate from the other. A small spanner or a pair of needle nose pliers will remove the exposure dial. Take it apart and clean or just tighten if it is clean. A little loctite, light duty, never hurt.
To find the rattle (mine rattled with a half broken switch contact spring), remove the screws under the serial number tag at the base. Maybe that is what you've done. Then, remove the viewfinder lens where your eye goes. Seems as though it unscrews somehow. Been a long time. Then the cover should come off.