4-speed & black carpet is 68-69 RR coupe & HT, owned originals of both, in base & Decor Group trim levels. May also be a 70 deal.
Higher trim levels - above Satellite/Decor Group - may have had colored carpet, according to some guys with GTXs.
As for the A-bodies I can't say, but Chrysler's philosophy was always biased towards reducing expenses, so if they could save a few cents per car, that seems to have been the mantra.