[Reece]

Use one probe of your meter and leave the other disconnected. This way the probe wire becomes an antenna. Touch the probe to pin 3 (the one by itself) on the 27 tube. Should get scratching and hum, maybe a weak station (not tunable). Then proceed to the 24 tube just in front of the 27 and touch the top cap: should get noise and maybe a weak station. Keep working towards the antenna on the top caps of the 24's. If you lose noise/signal, trouble is in that stage.

If the trouble is in the very first antenna coils etc., remove your outside antenna wire and touch it to the top cap of the first 24 at the left on the schematic, then the second, etc. This will also isolate a stage.

The schematic calls for 2.5 volts at the filament windings of the transformer, so if you're getting 2.3 at the filaments of the output tubes that's reasonable and the ballast is OK. All of these tubes take whopping (for a tube) amps to light and could use a cleaning of the pins and the tube socket contacts, but first you need to get it going again.