The ocassion was 1953. An all-Sibelius concert in Helsinki, with the composer listening from home in Järvenpää (he was 88 then). The younger (by sixteen years) Stokowski does his magic here, no doubt. For those of us who love his conducting (he is always so full of fresh and compelling ideas!) this is a must. You can hear a piece in dozens of versions, but Stokie makes you listen to it afresh. It's magic because I simply don't know how he did it.
For his conducting and the sense of ocassion (CBS radio network announcements included) this is a great release. But the tape (or source) shows severe deterioration, becoming quite uncomfortable at times. You have to make a true effort to perceive the magic behind the distortion.
Worth it, anyway, depending on your priorities and the price offered.