Shelter 901 "not up to today's performance levels" ? :-)))
It's not a computer, it's a cartridge. Good sound doesn't go obsolete.
Going by your theory, the Grace F-9 Ruby or the clearaudio Insider are also not up to today's standards - because they're old? You don't notice that today every cartridge is going for more and more detail, and more and more high frequency extension? Today, even (the used to be soft sounding) Sumiko, Goldring and LINN cartridges sound bright. You like this kind of "progress" ??.....
Today's "standard" is garbage.