I had a '69 Dart WSS in the early '70s - T7 I think (dark bronze anyway), black VT & interior, 318/904/AC car. Last known whereabouts Big Bear, CA. I removed the "Western" lettering one day but left the rest...you know, hopping it up. The side moldings seemed different than the other Darts that had them from the factory; no insert and rather narrow.
It was a regional trim deal, like the Mustang California Special & etc.
For whatever that sketchy info is worth...