Postwar Dummy HO F Unit w/Horn Question

I don't ever remembering any instructions for that unit. One thing I noticed is that is not the right controller for that unit. The controller is really weird, it has a spring powered large copper disc that spins about 1/2 revolution then stops. What it accomplishes  is it interrupts the track power for a second which trips the 2 position reverse unit. 1 push of the controller button turns the horn on, another push turns it off. The lead power unit jerks a little when this action happens. The horn vibrator uses 2 AA batteries.  It doesn't sound too bad for a single chime horn, better than expected. The HO whistle tender triggers the same way. I don't understand the engineering of the controllers spinning disc. Maybe some one here can go into it. That's about all the information I have. Service manual is of no help either.

Thanks Chuck.  Two AA's won't work.  The twin contact is actually one piece.  It appears to take a "C" cell with the positive end making contact with the reverse unit which has a wire attached to it.  The controller you describe is certainly an odd piece, have never seen one.  There has been a couple of the B units on the auction site with a photo of the top half of the instructions but not all the page(s).