[OZ4]

No P-P is plate to plate that should be an AC voltage. P-P in the transformer voltage chart.
On the 80 tube P-K would be from either one of the bigger pins to either one of the smaller pins and is a DC voltage.
From the drawing it shows the larger pins are the filament which is also the cathode. (that's K for cathode)
The voltage I would be interested in is across the #60 filter cap which is also the output of the power supply and is not in the chart.