Hi, yeah it must be cool to be looking at something you made that long ago. Probably the easiest way would be to power it up with a series limiting light bulb, and an auto-transformer. With the auto-transformer, you can dial the AC voltage up and down, and slowly turn it up, and let parts like capacitors, get used to all the voltage again. How long all that takes, and at what voltages, IDK tho.
And the series lightbulb, like 100W or more, helps when the DUT doesn't use that much current, so maybe a few hundred milli-amps. But if for some reason, the DUT becomes a short, like a cap blows up and short circuit, or if you accidentally short the hot side of the DUT to GND, then all that happens is the light bulb can use as much current as it wants, and just lights up.
The DUT and the light bulb form a voltage divider, and if the DUT is low impedance and can use a lot of current, a lot of voltage can be dropped across the light bulb. So sometimes thats good too, as a way to limit the voltage to the DUT. Other times you need a higher power, lower resistance light bulb, if you want the DUT to fully run.
But without a big heavy expensive auto-transformer, you could apply some low DC voltage after the rectifier tube or diode, but 12V or 24V won't get far in a circuit meant for hundreds of volts.
If I really wanted some higher DC voltage, I might tap off the 170V after some rectifier, in say a computer PSU, And then if I only wanted a few milliamps max, to charge up some caps, I'd use some series resistor. I would not try pulling any amount of current that way. But yeah I wouldn't try that, I have an auto-transformer anyways.
Ok and you have an isolation transformer with taps. Yeah just start at 25AC, and leave it for a few minutes, maybe more, IDK. And them move up to the next level, and repeat. But yeah if you add a series light bulb, that should save your radio, if some something goes short to GND.
I'd also say go on youtube, and watch some old VT radio repair video's. Mr.Carlson does lots of nice restorations, and there's some old guy Shangoo ?? that will get some 60yo TV working, that he finds out in a desert landfill.
Also, I'd check as much unpowered as I could, even if it meant unsoldering some caps.