The wheel pictured is a "
Grant 246 Classic Nostalgia Steering Wheel" that has been stained darker and clear coated to more resemble the factory Challenger Rimblow steering wheel (Option S83) in the first picture below. Instructions for horn switch and center cap below.
The correct color for the factory woodgrain wheels is Pantone PMS 477 (Dark Brown but called Redwood).
Challenger RTA posted a picture of the Tuff wheel hardware in his response above (1st response to original post).
You are looking for "Mopar tuff wheel horn switch" to get the correct part plus the center cap.
YearOne has the these items as well as many other vendors. The repro Rimblow style center cap for Challengers and Cudas is much more expensive as this was a rare option.
The Tuff Wheel (LEFT) was never offered on E-Bodies but is very popular.
The 1971-1974 Standard Wheel (RIGHT) center horn button and horn switch will work with the Grant 246 wheel.
Horn Switch and 71-74 Center Cap