My wall outlet measures at 125VAC, so I used a variac to step down the voltage to 117VAC to match the Sams. According to my Kill-A-Watt, at 117VAC, the TV uses 302 watts and 2.92 amps, which is within 5% of the Sams spec.
Stepping down the wall outlet from 125VAC to 117VAC made the arcing clicking and ticking sound from the HV cage completely stop!
The most readily accessible areas to probe B+ and Boosted B+ are the blue circle and red circle in the schematic, that is, the two leads of the spark gap, which are right above the blue screen pot. The B+ measurement should be accurate at this point, but the boosted B+ should be lowered by the resistor network in the screen grids to 1012V.
B+ measures 383.12V, which is within 5% of the Sams spec of 370V.
Boosted B+ measures at 960.92V, which is within 5% of the Sams spec of 1012V (the theoretical voltage if each pot and resistor in the screen resistor network measures exactly to spec).
So B+ and Boosted B+ appear to be good. I will measure ultor voltage and focus voltage tomorrow. I bet focus voltage is low, which would explain the blurry picture.