Best Vinyl Bach - Solo Cello Suites recording?

I hope you got the latter of his two recordings , 1992 I think, where he plays the famous strad from the Smithsonian
Collection, just for the sound.
But Bylsma's earlier SEON recording now on Sony is fine as well.

I believe the original instrument crowd thinking this music should be played on the instruments it was written for are spot on. Bach wrote for the Lord of the Dance.
The Cantatas are the heart and soul of Bach, they were written to aid the prayers of devout believers not as the
mini-operas being recorded today.
Most illuminating are the one voice to a part series by Sigiswald Kuijken's "Le Petite Band" which sound just like what they are, simple Christians at prayer.
When Bach signed every work "To the Glory of God" that is exactly what he meant.

I was ready to recommend either of the Bylsma recordings, but then I saw your post. The earlier recording, on the Seon label, is very good; it is somewhat drier in sound than the Starker or Rostropovich, but the pace and tone are are, as you say, fine....and maybe better than that.
He slows himself in the later recording, and there is a bit more richness and treacle, but I didn't think this was available on vinyl. I would be very interested to hear otherwise.

I hope you got the latter of his two recordings , 1992 I think, where he plays the famous strad from the Smithsonian

Yes.

Fully agree that authentic instrument (and vocal style) performances are preferable (assuming a good performance of course). 30-40% of my ~4,000 LPs are such, including (for example) the 45 volume/90 LP Harnoncourt/Leonhardt Cantata cycle. I am not particularly religious, but hearing Bach's Cantatas performed in the spirit he wrote them could almost make me so. Modern, operatic renditions are also a travesty to my ears.

IMO original instruments give Bach what is needed, less precision and more mystery .Even more called for in vocals.

I am religious, but was not when I first heard the Cantatas
and Passions, but being Christian has brought new depth , to me at least.
Masaaki Suzuki. whose operatic style series on BIS has been
widely lauded, says you don't have to be Christian to understand Bach, that's as may be, but it sure doesn't hurt.

As an atheist and someone who is devoutly anti religion, I can also appreciate music by superstitious 18th century musicians…it's easy.