Factory A/C in 1967-1972 Darts

I am I retired engineer who has seen many times how data taken incorrectly or poorly can cause incorrect conclusions

Sure enough. But you're also the dude who can't seem to get his Duster's A/C to work well, and who didn't know about the A-body systems not using an EPR valve til '74. I'm not saying that to rub yer nose in it, just to point out that there's always more for all of us to learn, even on the subjects we already know a lot about. Extensive knowledge on a subject can actually blind us to stuff someone with less experience might notice more easily, or question more readily.

Those high-side pressures that look alien to you don't imply that the tests were somehow rigged, just that the test system wasn't like the cars you're used to. That doesn't really matter; the important thing is that everything was kept constant except the two kinds of condenser. If they'd tested one kind of condenser in a '96 Toyota Corolla and the other kind of condenser in a '78 Chevrolet Caprice or something like that, that would've rendered the tests useless.