EDIT: Your spacer, or also called locking washer, is 90 deg off. Turn it 90 CCW. I believe the short bent leg goes vertical into the long vertical slot. That would put the shaft into the rearward slot. Then star washer and nut on threaded shaft. Bend one small ear, on the lock washer, up to lock the nut.(whichever one is parallel to a flat on the nut or both up).
