[cathoderay57]

OK, the MU14 is indirectly heated and is probably the reason for the high HT. It's a long-shot but before doing anything else check C44 the speaker field shunt capacitor since if it has gone very leaky it will be reducing the voltage drop across L35. To bring the HT voltages closer to spec I would recommend inserting a couple of dropper resistors as follows. In between the top of T1 primary and the HT rail insert a 1k 5W which should drop the N41 anode voltage by about 40v. Make sure the new resistor is only in the part of the circuit that drops the voltage to T1 primary because the HT feed to the rest of the set could be taken from wires also soldered to T1 primary tags. Re-measure the cathode voltage and if it isn't less than 5v then increase R37 from 100R in small steps until it is, to increase grid bias and reduce the anode current. Also insert a 1.8k 2W resistor between C45 (west of the connection to T1 primary) and the HT feed to the rest of the set. The total HT current budget for V1, V2a, V3, V4 and V5 screen is about 23 mA so a 1.8k should drop about 40v. There is a separate HT feed to V2b oscillator to improve frequency stability but the excess voltage on the oscillator anode is probably OK to leave as-is. Cheers, Jerry
P.S. Also worth checking the dc resistance of L35 the speaker field coil. It should be 1.1k but if the speaker has been replaced at some point it's possible somebody fitted an energised speaker with a lower field coil resistance.