7 & 9 pin "miniature" tubes don't much care about conditions---the working bits are sealed inside, after all, & the pins are quite rigid.
Octals may suffer, because the connecting leads inside the plastic bases are a bit more flimsy.
Lost vacuum is usually the result of "one off" sealing problems in service, or rough handling of loose tubes.
Even though I have no real space for a 500 series CRO, I would grab it if it were nearby at that price.
I have to disagree with you there, unless the outside environment is very dry, i.e the desert mine dumps, that a certain Youtuber has found old TVs & radios to resurrect.
In the UK outside with plenty of rain, or damp leaky sheds, lofts, garages etc. is more typical. The tube pins corrode to the point they crack the glass and you can say goodbye to the vacuum, or the neon fill for volt-ref & display tubes.
Example from a 50MHz hp scope, 2/3rds of the glassware was cracked and it didn't matter it they were German, British, Dutch, US or Japanese, etc. brands, they failed they same way.
I was able to rescue enough OK tubes to get the vertical input plug-in going and a couple for the delayed timebase plug-in, but that was it. The rest became a parts donor, as I have three of them that are in much better condition.
David
Wow that's a lot of white tubes indeed !
Still not a showstopper in the case of this 547 since again, that would be dead easy to spot when I would have looked at it. Hell even if not in the flesh, on pictures alone it would be easy to spot.
Plus if the pins are corroded that bad, there would also be obviosu signs of corrosion everywhere else in side the scope, would also be easy to spot even remotely on pictures.
My take on it, based on the picture an extensive experience of French sellers on that website... is simply that this scope has been pulled from a garage and put on that terrace / garden simply so the guy can have broad day light to take decent pictures of it. Many of the scopes I bought were taken pictures of in a similar fashion and none appeared to actually have been living in the environment the pictures were taken at. Thankfully.
If that scope had indeed been sitting for years outside where that pic shows, the outside of it would be in a much worse condition I think. There would be nothing left of the side covers to begin with. Like no paint left, just rusty panels.
I just don't see the decorative value of that scope in a garden. If just for that it's unlikely it would have been sitting there for years under the rain...
Again... its condition would be obvious once seeing it in the flesh, so it does not matter the speculation and guesses. If it's just down the street you simply go have a look (armed with a screw driver to open it), and be done with it. Like it, take it. Don't like it, don't take it. Simple...