Made good progress with replacing any out of tolerance resistors along with the waxy paper capacitors and Hunts Mouldseals - haven't touched anything in the FM section though.
Some of those Hunts caps just crumbled when I tried to remove them - here's a picture of some of the casualties: -
The good news is that I'm still getting a good strong signal on Radio 4 LW while I now have many stations available on MW that I never had before. Signal strength is now good on both LW and MW.
The bad news is that there is still absolutely nothing on FM?
I did have a minor mishap due to a rogue solder blob at the junction of R14 and C28 (Trader Sheet References) where the pin from L19 had been inadvertently earthed to the chassis. Removed the blob with solder braid and it turns out there is only about 1mm of clearance between the pin and the chassis at this point.
Voltages on V5, V4 and V3 are all much improved following the replacement of the Hunts caps but then things start to go awry when we come to V2. I was very careful when replacing components on the underside of V2 because of the very cramped space around the B9A valve-holder but there are no short circuits or dodgy solder joints.
For V2 (ECF82) and V1 (12AT7) the voltages I'm reading for AM and FM are: -
The 12AT7 still has no signs of heating up and is cold to the touch even after the set has warmed up. Clearly something amiss here but not sure where to go next. A bit wary of going into the FM section to change anything as realignment may be required after that!