Your wagon’s color looks like the light gold Poly - same color as a Valiant convertible I used to have and a 65 Barracuda I parted out.
You should be able to add the dual exhaust (double exhaust). The Barracuda I parted out has the same floor pans as your Valiant and had dual exhaust. I had a 65 Dart back in the 80’s where I added dual exhaust. And I will be adding dual exhaust to my 65 Dart wagon.
FWIW my wife and I visited Switzerland last year meeting up with another FABO member. We’re going back next year visit with them again.