I hope this will help someone... I was quite chuffed working it out!! Problems : intermittent horn and annoying use of horn while turning the wheel. Solution 01... Looking at the brass ring on the base of the wheel it was worn in a couple of places where it rested in the terminals and generally sat a bit low compared to the outer rim so wasn't making a good connection. I bought some 5mm copper tape for relining scaletrix tracks and used this to cover the old brass ring. Added to that I placed a couple of washers below the plastic to keep it proud and allowing the terminal below to maintain contact. Solution 2... In order to stop the horn going round corners, I very simply taped up the screws connecting the plastic base to the wheel which were completing the loop when my sloppy steering column moved around its hole... Having re-read that I think it might be useful, but if not there's enough innuendo to keep peeps going
