I heard of an Ellington scholar who transcribed two early Ellington releases and they looked to be note for note. They realized that they had been recorded on adjacent mics and cutting decks, and if combined would yield... wait for it... stereo, decades after the original recordings were made, having been done before stereo existed. (This was from the direct-to-disc era so they could issue more pressings that way.) I don't know how they dealt with speed diffs between the two cutting machines and keeping the phase relationships correct.
That being said, I have never heard a 'enhanced-stereo' (originally mono) recording that didn't sound like crap, so they're usually easy to identify. '54, I'd say near-zero chance of it being true stereo.