[Arran]

One thing to check on, while you are in there, is the candohm resistor I mentioned, sometimes those have a habit of developing open sections, but you have the resistance readings listed on the parts like under R12 so you can see if it's still good. Another area to check on is the speaker plug socket, to me it there does no seem to be enough wires connected to it and there should be at least three. One should be connected to the cathode/filament of the rectifier tube, one should be connected to the positive end of the output filter capacitor and one end of the output transformer, and the third should be connected to the plate of the power output tube.
In some cases they will add a fourth connection to one end of the output transformer rather then sharing one with the output side of the field coil. This set looks like it uses a six pin speaker plug socket, in some of my radios, Rogers made sets in particular, they will use the extra pins for a jumper just to disconnect the input filter capacitor from the rectifier tube filament if the speaker is unplugged. Sometimes they will add another jumper just to disconnect some other portion of the power supply circuit. It would have been nice had Philco included this feature in their model 18/118 sets rather then their traditional four pin plug, those sets use the speaker field coil in the B- circuit so if it is out the B+ will try finding a return through other parts like 1/2 watt resistors.
Regards
Arran