The other measurements are in spec
Well the kt88 control grid is a few off.
Ss rectifier (2) uf5408 (1) 100ohm25w resistor
Wall voltage 120vac
Pin 4 to ground - 400 - 425 volts AC. 417
Pin 6 to ground - 400-425 volts AC. 417
Any 6550/KT88
Pin 1 to ground - approx .550 volts DC (depends on bias setting) .450
Across pins 2 and 7-6.0-6.5 volts AC. 6
Pin 3 to ground - 470 - 500 volts DC. 480
Pin 4 to ground - 470 - 500 volts DC. 480
Pin 5 to ground - minus 50 to minus 60 volts DC. -47
Pin 6 to ground - minus 50 to minus 60 volts DC. -48
Pin 8 to ground - approx .550 volts DC (depends on bias setting) .450
Quad 1 480-505 volts DC. 488
Quad2. 470 - 500 volts DC. 481
Quad 3. 470 - 500 volts DC. 481
Quad 4. 400-430 volts DC. 411
Central 12AT7 - Pin 1 or pin 6 to ground > 130 - 160 volts DC. 142v
Two outer 12AT7's - Pin 1 or pin 6 to ground > 255-285 volts DC. 256v
Any 12AT7 - across the two incoming heater wires > 6.0 - 6.5 volts AC. 6
"-50 VAC" on driver board > 48 - 55. -75
"B+" on driver board > 400 - 430. 412
"G" on driver board > 0 volts AC or DC. 0