Hi Bob,
Next time, cover the stab before you permanently install the horn. That way you can run the silkspan'polyspan all the way across th stab in one piece which seems to add just a touch more strength.
For now, just do the best you can to get the polyspan as close to the wire as possible and seal it well with dope. You can clean off he wire a bit after finishing and before you mount the elevators so that it doesn't bind.
Bill <><