. . . a plum by any other name would smell as sweet . . .
I totally agree about seeing a sample sprayed on a panel. I would have liked to, and should have, but I was impatient and liked the sample paint the shop mixed up and showed me on a stick. I realized later they were just saving time by not spraying a sample and then needing to clean up the gun, etc. But I could have insisted. In the end, I don't mind if it's not the same as anyone else's Rosso or Prugna, I am loving the look of it. But other owners might not feel so flexible.
The AR numbers are interesting--somewhere on the forum I saw a post with reproductions from a color sample book from '71 (? I think), and according to that page, they had two AR numbers for Prugna, for that year only! So, does that mean AR listed two different numbers for the same color, or did they have slightly different versions/formulas that were both called Prugna? One of the issues that also complicates all of this is that the types of paint easily available are so much different than the paint used in the '60s and '70s. With that in mind, I feel very happy about what my car ended up with.
Most photos of cars we see probably aren't entirely accurate renditions of their color, dependent on the light source, angle, camera quality, etc., and the scans of color charts can be off, too. Add to that the variations in color settings and quality of different computer monitors, one really can't depend on images to tell for sure.