I've got a 1968 RS Convertible with two-tone interior - the seats and door panels are gold with black accent. As you implied below, the top part of the door panels are a different color. In my case they're black on top but the rest of the door panel is gold. The seats are gold in the center (about 18" wide), with black surrounding the rest of the seat.
The car was built in Los Angeles, and I was told the interior was special ordered. Everyone I've spoken to (Rick's Firstgen, Classicindustries, etc..) says this two-tone interior was not an option and must have been done after production. I don't have the protecto-plate and have yet to search for the build sheet, so I'm SOL for now - unless you can state that you've got something similar.
One person at Classicindustries said they knew of this special order interior and said it was very rare.