I really appreciate Tom and John for the great information concerning the previous blog post.
I learned a lot! Also thank Manuel for a great comment! This Hank Mobley Blue Note BLP 1568 session was recorded in 1957. That is the time of transition from MONO only recording to STEREO recording.
John shared a screenshot of the actual tape that this session was made in 1957. This tape surely was in STEREO! Toshiba EMI maybe...used this master tape to create the STEREO version of BLP 1568! No concrete evidence that they actually used this tape but maybe...
I will send you an audio sample of BLP 1568 STEREO reissue by Toshiba EMI as my 1st "Weekly Jazz Audio Challenge" on Monday. So just listen to it by yourself, OK!?