Advice for buying a tube-era TV?

[vintage.digi]

I’m considering driving this weekend to inspect and hopefully buy a 50s TV, and this is older than the majority of sets that I’ve dealt with in the past. What do I need in order to safely test it? Do I need an isolation transformer?

The seller posted a picture showing static and says the photo was taken yesterday. I can take something to display a picture pretty easily. I do have a tube tester but if the whole unit is working then I wouldn’t think I’d need it.

I briefly had a Predicta once, but the second time I plugged it in, it started smoking, so I sold it to someone who had the knowledge to service it. That wouldn’t just be due to the hot chassis, would it? I don’t think home users had isolation transformers at the time these were in use.