I cleaned the wheels and added the spring for the copper pickup and it runs. The reverse unit is a little mystery. The last picture is half of one from another junker. I do not have a date for this engine either. The light socket is insulated from the frame. So the sides are hot and the center...

This is the 1666 that was in the box. All I can think of is that the springs are used for track detection. Not a bad idea really. Today you can dress a postal car with a small spring to make contact with a postal pole. It would work. but it is not a fancy infrared sensor or reed switch. Thought...