Son_Of_Dog
Unfailing Millennial
That could explain the bit toasted white wire, and maybe some more toasty wires... in my MG I had a short circuit with the cigarette lighter lamp. Cause a LOT of troubles in the entire wiring behind the dash.
Maybe a good idea to check the wiring from horn switch to main harness.
The horn currently works quite well, so I'm thinking that wiring is probably okay.