Car ID

So, with a quick search here's the numbers I found...

From this post, with no source info given...
Interesting A-Body Production Numbers

1972 Duster

Fastback Coupe: 212,321
340 Fastback Coupe: 15,681
Total 1972 Dusters: 228,002

High impact paint %'s, which only shows info for two colors in 1972, hemi orange and lemon twist. Winchester gray isn't a high impact color, so, maybe no data on that at all
High Impact Color Production % #'s

Allpar, which lists the Duster and Valiant in the same category...
Plymouth U.S. Model Year Production Figures, 1946-2001


This post, which says 212,311 Dusters in 1972 and lists a source but no 340 breakdown (post #5)...
Demon vs Duster Production Numbers.