Steinar - yes, it could be more valuable in 10 years. When you have a bottle of Scotch from a closed distillery, it certainly is considered rare and definitely has more appeal! As to value, it's basically what someone or a collector is willing to pay. Of course you can go by or use as a guideline what other bottles like yours have sold for in the past. As for whether it's drinkable - yes, it should be fine. You may hear different opinions on this, but just keep it out of sunlight, avoid extremes of temps and store it upright (don't let the cork come in contact with the scotch). I was able to get more info on your bottle - courtesy of Glenlochy's parent company - Diageo. See attached.
