A new door system and related technology for a passenger carrying rail vehicle, such as a President's Conference Committee (PCC) streetcar rail vehicle, and a method for retrofitting a rail vehicle door system with the new door system. In some embodiments, the new door system includes an electro-mechanical angle drive motor, a solid door control pivot rod, a door leaf panel clamp that is permanently connected to the solid door control pivot rod, a lever arm that includes a positive locking device and that is coupled to the solid door control pivot rod, and a connecting rod that is attached to the electro-mechanical angle drive motor and to the lever arm to enable the connecting rod to impart motion generated by the electro-mechanical angle drive motor to the lever arm.