I fixed the horn push today. After posting on the Club Triumph forum it seemed that virtually nobody has made a Mountney horn push work! I have and here's how I did it! Basically I didn't bother soldering a wire between the 'pencil connector' and the horn push, instead I drilled out the rivet holding the crimp connector on the back of the push and instead rivited a strip on metal along the back along with another rivet to keep it from spinning round. This makes contact with the 'pencil connector' and completes the circuit when the horn is pressed. Job done!