We’re guessing there probably is not a whole lot of this lovely Scotch whisky. It was distilled in 1991, bottled in 2006, and came to market shortly thereafter.
The Glenrothes website has a very informative web page and video at http://www.theglenrothes.com/uk/products/vintage-1991/
There’s more to this Scotch than the alluringly retro packaging. The Glenrothes 1991 (86 proof) is a very interesting drink. It is rather viscous in the mouth, and thus very smooth. One detects notes and flavors of orange, butterscotch, cocoa, and more. Take it straight up in wee sips and squish it about your mouth to get the fully effect. Mmmm…. (Rating ****1/4)
If you are lucky, you might be able to get a bottle through an online retailer.