Xtra old particular caledonian 42 year old 1976

I had to research this distillery since I'd never encountered it before and sadly discovered it ceased operations in 1988. My sample came from a bottle in a premium range, a very old single grain spirit from a distillery in Edinburgh. Distilled many decades ago and aged in a specific type of cask for over 40 years until it was bottled at full cask strength. My prior experience with single grain scotch was from another distillery, which I found smooth but uninteresting, so I had low expectations for this one. Based on that previous encounter, I initially assumed this spirit from a defunct single grain distillery would be mediocre and primarily a novelty for those seeking extinct whiskies. I opened my sample, sharing half with a friend so we could both say we'd tried something no longer produced. After pouring and raising a glass for our initial drink, I took a sniff and was immediately proven wrong. It has a lot going on with no alcohol burn in the aroma at all: floral notes, citrus blossoms, apple, stone fruit, lemon candy, nuts, vanilla ice cream, very subtle oak spices like cinnamon, and the scent of fallen leaves. The taste is equally impressive with no alcohol burn on the palate either; it's very oily with a full mouthfeel and notes of sweet floral nectar, powdered sugar, apples, citrus blossoms, rose water, more lemon candy and nuts, with very subtle oak spices providing balance as it transitions between fruit flavors until it concludes with a medium-long finish of melon, citrus blossoms, lemon, and vanilla caramel that persists for several minutes. I was so impressed, I searched for a bottle, but sadly, bottles from that specific cask and vintage were no longer available. However, I managed to acquire a slightly older bottling from the same year of distillation from a reputable retailer, benefiting from duty exemptions as single grain spirits appear to be exempt. I hope to find similar flavor notes from a different cask.