65 Dart Horn Problems

Yes, to both your questions. The steering wheel and Steering shaft are indexed, or so I remember, and should only go on one way. With the front wheels straight ahead, typically that is with one of the steering wheels spokes pointed down at the 6:oclock position. The looped, round steel retaining ring should be positioned so that the vertical leg (not the looped portion against the horn retaining ring) ends up in front of the turn signal cancelling cam roughly aligned with it's center and/or the turn signal lever arm screw. Mis-alignment hurts/damages nothing, has no effect on horn function, it just makes the self cancelling mechanism cancel or not at odd places.