Easier way to go would be to place a bi-directional TVS diode across the CRT filament. Done.
I used this one:
Diode part no. P6KE8.2CA-TP. Got it here:
https://www.arrow.com/en/products/p6...ponents#page-1
Just follow the wires from pins 1 and 11 of the CRT (Heater). Wherever they connect in the set, put the diode across those two tube pins. Protects the CRT from the start up surge and no separate transformer needed and no need to compensate for the missing CRT heater in the rest of the string. If I remember correctly, I had to extend the leads off the diode, but installation took about 5 minutes.