[russell_w_b]

You could always disconnect terminals 1, 2 and 3 at the dial strip tag-block: that will remove the D.O.N contacts from cct. It might be easier and less damaging than trying to poke sweetie wrappers, bits of paper or what-have-you between the contacts.

When you adjust the cam, you'll need to remove the dial from the telephone. To do this, remove the small screw at the six o'clock position inside the dial aperture and twist the dial anti-clockwise about an eighth of a turn, looking from the front of the telephone.