I am going to make a guesstimate here. Without seeing the set up I would say the pivot point of the bracket should be in line with the rudder hinge line. The spring sounds like one end goes to the bottom of the rudder and the other to a tiller coming off the top of the bracket. The metal wire would run up through the bracket and turn towards the rudder at a 90 degree angle to the bracket. The spring would act as a shock absorbing device to keep shock loads off the rudder servo. Look at a Sullivan set up. It sounds an awful lot like one of thier set ups. I hope I didn't confuse you too much. Good luck with the model.

Mark Shuman