i think when we hear pre-50's recordings they are not relevant to the Lp era recordings, and are more for an historical perspective of musicianship and not sonics. unless you are playing original 78's which is a whole separate case. so our expectations should be matched to the situation. there is no 'original tape' to use as a source to get a 'better' copy. they copy the original pressing.
in the modern Lp era (after 1952 or so) with modern tape decks doing the recordings (both mono and stereo) now the quality of an original pressing verses a re-issue is in play. and although results can vary, mostly original pressings in decent condition will be the best way to hear any recording. maybe 45rpm re-issues muddy that water somewhat. and certainly there are many re-issues sounding better than original pressings we might find. but that unicorn clean original will still be the holy grail. and when you are talking mono originals, they don't need to be visually in such great shape to sound fine, since surface abrasions don't harm the groove on those mono deep grooves. having a mono cartridge with the larger stylus size makes a difference on those. some really apparently hammered Lp surfaces can sound fine.
it's lots of work, and $$$'s, to find early or original pressings. mostly re-issues can be very good. there are lots of re-issue series that can be reliably counted on to have great sounding Lp's. so chasing originals is not necessary.