[traveno]

Holy hell that is definitely a nightmare. Unfortunately I can't offer much advice because I know nothing about stereos. I do, however, offer you my condolences. I hope you can revive the car's stock configuration. I'll keep you in my nightly prayers in the meantime.

Looking at the stock wiring diagrams would be a start. You'll have to restore the harness as best you can to how the wiring diagram specifies. Theoretically, it should be plug and play then. Assuming all components are back to stock.