[Techman]

That looks absolutely perfect!

That radiogram obviously hasn't been dragged up a rough concrete garden path.

You'll have the 'audio' nutters banging on your door to get their hands on those valves!

If you haven't already done so by now, you'll have to work out from the circuit diagram where the first smoother is. You can see the rectifier which is a 'direct heated' type. Being directly heated, its filament/heater is the cathode, so you'll need to identify the connection of the filament to transformer MT1 winding L28 where it also connects to L27 with R50 and C49, this is where you need to clip your meter.

The capacitor can in your second picture above may not contain C49, but I note that the end cap of it does look very slightly 'bulged', so it may be that this can will need replacement. However, this slight bulging may have taken place decades ago when the gram was run continuously for many hours at a time, so just keep an eye on any slight warming of the can between your tests or lack of the HT rising properly. Check for any signs of slight warming of the cans of all the electrolytic capacitors, and be aware that under certain fault conditions they can hold a lethal charge, so check they're discharged (measure for any voltage with your test meter) BEFORE touching any connections - even when disconnected from the mains.