Yoda - you wrote-: "All he asked was that golfers understand the necessity of a fixed point at the top of the Pivot (Pivot Center / The Glossary). He recommended the Head but did not mandate it (2-H). In fact, he offered an alternative, i.e., the "point between the shoulders" (Stationary Head / The Glossary)."
I don't need to draw lines on those photos for forum members to mentally picture the location of the upper swing center. It is defined as a point midway between the shoulders - which is roughly a point within the chest cavity a few inches in front of T2 vertebra. That point is about 2mm south-east of the C7 blue dot in those photos.
Jeff.
Just draw the lines, Jeff.
You've made this a big deal, and it is a big deal. You've been drawing lines for some 90 posts in this thread, and I've studied and appreciated every one. Don't wimp out now . . .