It's stereo, but just primitive, like the songs
Most of these recordings were never meant for stereo. Purists may want them in mono, as they were on the original vinyl. Here they're in a kind of "reprocessed stereo" which is not ideal, but is done with more skill than the fake reverb-drenched dual mono of US Beatles albums of the same era, or the even worse highs-left/lows-right sometimes used. Here a phase-shift is the main tool, and it works as well as one could hope, taking advantage of how clean the recordings are. That's more than enough for me. The really important thing is that these are authentic deep-tracks from the birth of modern rock, and at 49 cents apiece, they're ideal for cherry-picking - You must hear the original "Stop Your Sobbing" which was later a hit for The Pretenders.