Probably not an easy find, but would some resellers still have brand new analog scopes from A-brands in stock?
Occasionally that happens, yes (although not from Agilent as they never made analog scopes if I remember right, the analog ones were all HP).
Note that a friend of me bought a brand new Fluke PM3082 a few months ago, which was still sealed in a carton box. The actual scope was sealed in a silver-metal-looking vacuum bag.
The scope works like a charm, and I am a bit jealous now. Note that he only paid like 300 EUR for it.
I'm not sure if it's worth being jealous. If you're a collector then I guess a still unopened analog scope might well be an interesting find. But for practical purposes (i.e. as an EE) €300 isn't that great for an ~20yr old 100MHz 2Ch analog scope, and while it's "new" in that it hasn't been used before, being in a sealed box doesn't stop components like capacitors and even the plastics part from aging. It will also have vastly exceeded it's storage life, which means if the scope is sealed in a bag then the drier (i.e. silica gel bags) will probably be saturated, and depending on the environment it has been stored, there might even be beginning or progressing corrosion damage caused by humidity ingress.
And even if it's in great condition, it's still analog scope, i.e. very limited compared to even bottom-of-the-barrel DSOs of today.
If it's cheap (say less than €150) and comes with some kind of warranty then it could be a decent deal, but for €300 I don't think it is when for roughly the same money you can get a brand new Siglent SDS1102CNL/CML which these days is much more useful than an analog scope.