I would like to hear from anyone who has experience diagnosing Verticillium disease in Pistachia chinensis. In particular, if the tree was autopsied and if lab tests confirmed the diagnosis, what was the appearance inside the affected limbs and trunk?

I am looking at a large old tree, now removed (DBH 25" about 47 growth increments). Lower trunk cambium was alive, heartwood was sound, except for large internal stress cracks. "Rings" of barrier zones are concentric from the center (roughly analogous to growth rings, but more wavy), following the leading edges of internal cracks. Outside the barrier zones, large areas are stained gray. Darker flecks appear at the leading edge of gray staining. Gray areas look like a city skyline stretching toward the outer part of the trunk. Outside of that, the remaining wood is brown on drying, with some other dark flecking scattered throughout. Major reduction in growth increment began within last seven years, but was declining for about 20.
Higher in the tree, the inner barrier zones are not as apparent. The large limbs that were most dead/dying had the gray-stained xylem too. The staining extended outward to the bark in some places. Branches were dying back from the tips, with flagging of smaller branches first. Parts of the tree were still functional, but at least half the tree had died on top.

Identifiable stressors include nearby building construction about 27 years previous, possible trenching for lightpost wiring within last ten years & pavement with 5 feet on one side of trunk, irregular watering, soil compaction from foot traffic, use of "Balan" herbicide in root zone turf about 15 or 20 years ago. Armillaria mushrooms appeared around base of the tree within the last year.

No responses received so far.
As an additional note, many Chinese Pistache trees at this location have succumbed to similar decline, especially those planted in lawns. "Powers that be" aren't interested in paying for any laboratory testing.
I'm hoping to learn from other's experience and observations, hopefully based upon more solid confirmation by lab tests.