Nice car.
As for the trim codes, the VIN/Code program I wrote is based on info from mustangII.org. That info only goes back to '74, leaving the first three years in question.
For instance, my '72 wagon had the trim code "DB" (also not in any info I have).
So, the car was Ginger; what was the color code for that in '72?
Also, the trim code is "CS." From what I've extrapolated from the information, brownish cars usually had chamois (second letter = "T"), tan (second letter of code = "U"), or saddle (second letter of code = "Z") interiors. I'm *guessing* the "S" in CS may stand for "saddle." However, I've also heard in another thread of the brown/white combo interior. Plus, I don't really know what color "saddle" is. Maybe it's white. So the "S" may stand for "saddle." Or it may stand for "white" if that's different than saddle. Perhaps it stands for "special" (as in the seats and headliner are a different color than the rest of the trim) The "C" tells what style the seat vinyl is (example: "Manston," "Dallas," "Colton," etc.). CS may be '72 nomenclature for [C]orinthean vinyl addle. Later (by 1974) this code would have been CZ. Corinthean "leather" was actually an early name for vinyl and all of the years I've run across use the "C" to denote Corinthean interiors.