OK, I am at the start-up stage, I checked the power transformer outputs to the heaters and to the rectifier tube. I measure 240V AC going in, and see 750V over the rectifier High Tension input pins (pin 4 and pin 6).
I plugged in the rectifier tube, and switched on, the tube glows up nicely, and I measure a whopping 550 V DC at the first input pin on the turret board, at the first capacitor(22 microfarad, 450 V). The other high tension DC points at the next capacitors also measure much more than they should.
But, while all this is going on, I hear creaking noises, such as something warming up. Tube should not, so? A light draft of smoke starts to curl up from the very hot 22 microfarad 450V capacitor. Switch off.
So, apart from the issue of too much DC going into the system, why does the capacitor overheat? Polarity is correct. Rechecked wiring.