It is the same color and same code (G) as 1973 Green Vinyl for the A Body Line.
His cowl tag/trim tag has "G"
72 code for green was (E) and much darker.
I'm guessing code G in the lighter shade - was maybe available on some other chassis of Pontiac or other brand of A-Body (Olds, Buick, Chevy) in 1972.
And he/they refer to it as a 73 color -- in an A-Body Pontiac sense.
Thats the best i can make the most sense of it - but have not done the leg work to research it.
Or maybe it was a mid-year offering on one of those lines, or Poncho A-Body line, and we don't have the memo.
Car was built 4th week of March - 5 or 6 months before 73 production began.
It is stretching to think they reached months into the future, and pulled out a piece of light green vinyl, i freely admit.
But car does have that code and that color.
I think my first explanations must be involved somehow.
Time Machine would have been too advanced for 1972 technology.
How does a consumer even know about 1973 vinyl top colors in March 1972 - to pick from a color.
I understand your point of view.