[Healeys] Trafficator

[Ron Ray]

Folks,
 
Do the three set screws that go through the steering wheel hub tightened
against the edge of the back plate of the turn signal switch?
Or do the go in front or back of the plate?
 
The lower screw hole on my hub, for an original Derringer steering wheel,
does not appear to be in alignment with the other two holes 
 
I have two of the original pointed set screws. If somehow I manage to get
the third hole to work, will a standard allen head set screw with the
slightly conical end work?
 
 
Thanks.
  Ron Ray