Is it the negatives of the two 8MFD that are supposed to be connected to ground via the 175 resistor, and the negative of the 16MFD cap connected directly to ground?

This clearly shows, on the left hand side,
the two 8MFD do not share a connection to the resistor:

Image Link

And the 16MFD is instead sharing the connection to ground
via the resistor.

So it's going to take 63 years for someone to fix this.

I can't help thinking this is the reason the radio was given up on, and became separated from it's cabinet.
I hope the 5Y3 that had to live in this circuit is ok,
that wasn't the smashed valve I had to replace.

Electrolytics used for high tension filtering are usually connected in a pi arrangement with the caps as the "legs" and a choke (speaker field coil or separate choke) or a high wattage wire-wound resistor as the "lid". Negative to chassis.

Different arrangements involving a resistor can be used to develop a voltage used for biasing.

The other use for electrolytics is cathode resistor RF bypass. These though only have a low voltage across them and would be rated about 40V. Also negative to chassis.

Maybe if you can figure out what the various caps are supposed to do in your circuit a solution can be found. Could the schematic be linked?

Here's the schematic:
Image Link

Easy to see the difference if you look at where the two
8MFD caps are grounded in the schematic,
then in the image above, over to the left where the caps are grounded,
it is the 16MFD and an 8MFD that are sharing the connection to the resistor.
THe resistor is black in the image.

Re schematic: I could make out the connection points, but not much help if there was a stuff up in original assembly or subsequent servicing.

You mean a stuffed cap?
This is completely original.

Sorry , meant stuff up!

I think stuff up in original assembly.
That's why I'm taking it straight back when I fix it, to complain.

Seriously though, this would have been bad news for the owner I think.

I don't understand how the rectifier works, but it's the schematic that looks correct to me.

Find out soon enough I suppose :O

Assembly errors and undocumented factory circuit changes are not unknown.

STC632 that is my current project has changes to the cathode bias arrangements shown in AORSM including an extra resistor that, going by the state of the solder joints, are factory changes.

Trying to work out what to do in these circumstances is a problem to say the least.

That was bad The power transformer makes smoke
and smalls bad with capacitors both ways.
I don't think I trust the rest of it to buy another one,
it's almost as expensive as a working radio,
and doesn't look the same as the original one.

Have you tested the transformer out of circuit, ie are there any shorts to the body of the transformer or between windings?

And once it is out of circuit, by applying say 24VAC to the primary, the voltage of the secondary windings can be safely measured, while minimising risk of damage to the primary or secondaries if there is a short.

If all of the secondary voltages are low it implies that there is a short in the primary.

There was some resistance across the primary,
and no leakage to earth (tested prior to powering it).

I didn't see any point testing the secondary because
I don't have any spares in case it was no good.
Finding out it's no good ahead of time still ends with
the same result. No point messing with it now.
The smoke and smell says it's broken.

The replacement is $122 from EVATCO,
and doesn't look the same if I were inclined to buy it.
I still don't know if valves other than the one I replaced
are still good, so I fear it just gets more costly.
Been out of work for 3 mths, so the $100 already spent
on it was a massive stretch already.

Bummer though, it took several years of asking around
to come up with my first one.

I can see my own little tantrum happening there.
It has become irrational to keep going on it,
but when I removed the power transformer, and saw
a previous "repair" from a different point of view:

Image Link

The tape on the choke was only ever on the side that
faces the power Xformer.
I only cleaned the tape off the edges of the choke with a blade.

Now it seems obvious the power transformer was already
hot for an extended period of time when the radio was in service.
Maybe the reason it became separated from it's cabinet.
I think the choke is ok because the other side of it looks fine.
I can even read the text that it was made by ROLA CO in Melbourne. Not burnt at all.

The rule applied here, where the spec cap voltage is 525 Volts,
and the substitute is 450 Volt, the consequence is a hot power transformer.
Does that make any sense?

I have changed them in and out more than once now.
Of the three electrolytic now, two are 500 V, and the larger
is 600 Volt, there is a big difference in their size, and their cost.
Maybe you'd get away with it most of the time,
but I won't try it again.