UPDATE (just a little fyi): STILL have the same Sylvania (40's/bottom-getter/two hole*) VT-231 and a T/S Round Plate (metal top support), in each of my Cary monoblocks (per my 3-21-2021 post) and they are STILL performing splendidly, far as taking me from, "here" (my listening room) to, "there" (the recording venue).
There are a multitude of variables*, when it comes to purchasing vacuum tubes, whether NOS or new production. PERHAPS, the most important: your individual knowledge/research on the subject.
It's been my experience: the aural benefits/attributes of listening through a tubed system I value most, are (invariably) best generated by components equipped with NOS valves.