It had to be her 1959 Bach series, that is terribly poorly documented... *sigh*
She did three sets of the complete works of Bach. The one that Warner issued is a remaster of (and that you linked) tapes that were made between 1959 and 1967. I cannot confirm if that entire set of recordings were done on the same organ (though I'm somewhat safely guessing that they were), such that I can confirm that the 1959 sessions were done on the Grand Organ in the Église Saint-Merry in Paris (it's the church behind the Stravinsky Fountain at the Pompidou Center). However, I cannot find the original LP release of the BWV645 to confirm that the notes for the 1959 edition match the other 25 LPs from later years in that set. And, apologies that virtually all of the sources I'm about to list are in French.
Here is the source for the first 1959 recordings being on the church of Saint-Merry's Grand Organ: https://gallica.bnf.fr/ark:/12148/bpt6k8803665w
Here are two stoplists for that Organ:
https://inventaire-des-orgues.fr/detail...stmerr1-t/
https://www.organsparisaz4.orguesdepari...0Merry.htm
To complicate matters, the organ has fallen into terrible disrepair--despite restoration work in the early aughts. Currently, my understanding is that the organ is functionally silent, and so generally vintage recordings are the only way to recreated the sound at all, which means that the usual method of searching for videos where organists showcase an organ's stops one-by-one is less likely to be possible for this instrument.
Here is a 1951 recording on the organ: https://www.youtube.com/watch?v=U3Ej0GFbpX8
Here is a 2010 recording on the organ: https://www.youtube.com/watch?v=DoDUkLrfA0U
On the bright side, this is a Aristide Cavaillé-Coll organ rebuild, which means that any of the CC (Cavaillé-Coll) presets are a good starting point. (Romantic Church, Romantic Abbey, and the Menilmontant one are the CC presets that immediately come to mind in OTQ 2--though I might be forgetting some--and the FXP corner could have more.)
The organ is A440 with Equal temperament, which also simplifies the recreation process.
Now, to the trickier part. You can simply enter in a series of stops (likely skipping the Echo division because of limited space in OTQ) that closely match the above stoplists (and you can always google a stop name or find it in online sources like the Encyclopedia of Organ Stops http://www.organstops.org/ which usually have good indications what the closest equivalent will be in OTQ even if it's not obviously listed in the software), and you'll have a decent analogue of the original instrument, which you could then tweak in the note editor for each stop trying to recreate the original sound based on the original recording and two provided.
However, you will need to take into consideration the manner in which the original was recorded, as the microphone choices and placement, 50s era consoles, and the original tape deck will color the recording significantly--which is why no two recordings of the same instrument will ever sound "exactly" alike. I have found no information on exactly how the organ was miked, but I lean towards it being multiple ribbon because of the SPLs of organs that were downmixed in the church and routed directly to tape in-situ, but large condenser mics were starting to become popular at the time, so I can't conclusively say that they were ribbon. Also, the size of a four channel mixer at that time was equivalent to a moderately large appliance like a washer and dryer (not that a single-channel was much smaller), so whether or not that was "portable" for the project or not is an open question--in which case it could be a mono recording with one microphone (which too could explain the seeming proximity effect on the reeds). That said, if they went directly to tape that could itself be another "small" large appliance, as studios rarely used consumer-sized tape machines even if recording in single-track. It's further possible that it was originally a four track recording from a four track console, only the studio that has tape masters could tell us.
Either way, between the limits of tape and limits of any mid-century microphones, expect a large amount of high and low-end roll off with potentially some mid-high boosting (especially if it was one or more ribbons). I'm surprised how "centered" the reeds are in any of the recordings I've heard, so I don't know if that's a function of the organ case design (though the reeds are surprisingly prominent in the 2010 recording), if it was originally a mono recording, or very close-miked. I suspect it was close-miked (which you can emulate somewhat in OTQ with the dry-wet balance) because of how little room tone the remastered recording has, but it's possible that they even went to the lengths of putting up something to block room reflections (welcome to the joy of speculating of how it was recorded). If the proximity effect is involved (which could further explain the lack of room tone) that will also color the EQ significantly as all microphones change their axial frequency response based on the distance, angle, and volume of the source (which is why very few of the slap-EQ-on-a-bad-recording-and-it-will-sound-like-an-Abbey-Road-M50 plugins or tech typically work, as that takes really precise, quality equipment--that borders on the same cost as top-end vintage gear--in near-laboratory conditions to actually work). To replicate vintage hardware EQ and tape FXs will likely be best done in a DAW, though the standalone application offers some digital graphic and parametric EQ. I do know that the room size for that instrument is slightly above 50 meters, so that will be a good starting point if you're using the built-in reverb engine (that said--I'm amazed how dry and "close" the remastered recording sounds when compared to the other reference references of that instrument). Though I tend to prefer outboard reverb, either good algorithmic, or convolution when trying to exactly replicate something.
I do know that the original tapes are/were held by Art & Son Studio, Annecy (2018) to do the remaster. So if you want to contact them and ask if they have more "nerdy" information they'd like to share, you certainly could try that: https://www.art-son-studio.com/
On the one hand, this is a fairly straightforward emulation with OTQ, on the other hand, it can turn into a tail-chasing nightmare lasting for months on end. I'd caution to give it a try and experiment freely, as long as it's entertaining or enjoyable for you. Such projects can be quite rewarding--even when followed to the "bitter end," but that doesn't mean you're guaranteed to fulfillment if you find as you work that exact duplication of this isn't precisely your goal here (as the question of what makes her recording sound the way it does may be more about her "registration" which is the choice of stops used than the manner in which it was recorded or on what instrument).
Spotify:
https://open.spotify.com/artist/2xHiPcCsm29R12HX4eXd4JPianoteq Studio & Organteq
Casio GP300 & Custom organ console