[old_tv_nut]

Where does your 7500 volts number come from? A maximum tube rating, or measurement of a tube type color set? You should use a measurement of an actual set, as this would include some reasonable derating.

Note that tube sets used unregulated power supplies, so line voltage variations had to be accommodated. This is a problem with running vintage sets these days, as AC line voltages have crept upwards over the years. Nominal for sets in the 50s was 117v, but line voltages these days are often well above 120. Another characteristic of tube circuits is that there is relatively large variation in bias and operating currents/voltages even if the supply is regulated. This is due to both tube variations and passive component tolerances. Tube circuits were designed with plenty of head room between nominal plate voltage and B+ to accommodate variations in B+ voltage, tube conductance (see spec sheets), and resistor tolerance (typically 10%), with nominal tube operating current and voltage appropriately derated so that operation was still possible under extreme variations. Transistor circuits, on the other hand, especially with a regulated supply, had well defined variability determined mainly by resistor values, due to the high current gain of the transistors.

I'm not sure what you mean by "the vpp of the waveform inbetween the flyback pulses." It's the voltages across the active device that count for its operation; and it's the p-p of the waveforms on the flyback and yoke that you need to duplicate to get normal width.