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My vote is to just to the harness
It's difficult to assess the extent of damage from the picture. If it's just a wire or 2, de-pin and re-wire the damaged wires. More than that, replace the thing. It's not worth your time to re-do everything. Harnesses are plug and play.
That being said, I have a strong aversion to a quick fix and risk chasing random electrical issues over the next couple years. Meh.
Moth balls under the hood work well. The real ones, not the natural cedar nonsense. They stink to high heaven though, be warned.