I agree on the greatness of the mono recording.
However, the K2 has an annoying smiley eq. The bass is unnaturally boosted. Really annoying if you like to crank the sound up and have floor-standing speakers imo, both for the ears and the neighbours.
Hands down the best version of the mono Monk's Music on CD was mastered by Kevin Gray for inclusion in the Analogue Productions box set The Riverside Tenor Sessions on Gold CD. A stunning audiophile remastering.
https://www.discogs.com/Thelonious-Monk-The-Riverside-Tenor-Sessions/release/4373398
I don't have the entire set, but was lucky enough to find a sealed copy of just Monk's Music from this set. At one point Acoustic Sounds still had one or two whole sets left and also some single sealed Gold CDs from the set. I payed roughly $50 incl. shipping from a seller on eBay, but it was absolutely worth it.
Not to spoil your mood, Mike. I was happy enough at first with the K2 compared to the various stereo CDs I owned, but the K2 sounds rough and ugly compared to the silky warm tones of the APO Gold CD.
I do still have that now near mint copy of the K2 incl slipcase and am willing to part with it for a friendly price, though shipping from the Netherlands is relatively high.