The original wiring harness had natural rubber wire insulation with a braided fabric covering. The insulation deteriorates and flakes away, leaving a huge potential for shorts and fires- - - -as you've already experienced. Patching on the old wiring is like giving a patient with a brain tumor an aspirin for his headache- - - -treating the symptoms, not the cause of the problem.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!