From the cellar of my friend, teacher, and predecessor, and due to a lovely convergences of circumstances, shared with both him and one of my students. The low fill level doesn't seem to have affected this wine much if at all (but that's not necessarily surprising for Sauternes).
Broadbent says in "Vintage Wine" that the 1975 Sauternes vintage (which he rates 5 Stars) had both excellent botrytis and excellent acidity, and those both come through in this wine.
Chateau La Tour Blanche, Sauternes 1975
Medium-low shoulder fill. Warm, medium-dark amber with bronze reflections. Outstanding mature Sauternes nose, deep and rich, with abundant fruitcake, notes of caramel apple and honeyed apricot, orange blossom, nectar, barley sugar, allspice, and lots of mineral; nice sense of warmth and exceptional complexity. On the palate, lots of sweet-tart tangerine, fleshy apricot, and a touch of raspberry, with loads of lovely, rich caramel, and honey/nectar, then a long finish loaded with mineral and spice. Full bodied and very sweet, with fantastic presence, combining wonderful richness with outstanding freshness and great complexity; I’ve not before had a Sauternes that has such a phenomenal combination of fresh citrusy acidity and lovely caramel-laden notes. Needs time in the glass to freshen, round out, and show its best. A candidate for the greatest mature Sauternes I have had. Seems to be at its mature zenith, where it should hold for at least another 5 - 10 years, and I would not be shocked if it is still alive in 15 - 20, perhaps with even greater complexity. A memorable experience! 4.5 Stars [8/1/17]