The age of whiskey only counts when it is the barrel. After it is bottled, age doesn’t matter one whit. I doubt that they aged this very much originally. It was bootleg, and I am sure the emphasis was on turnaround. The stuff was probably pretty harsh originally. The intervening century would not improve this at all.
While whiskey does not “age” in the bottle, vintage whiskeys are good because they were crafted in a time when quality ingredients were used and distillers took pride in their work. Find a bottle of cheap “old grand dad” from the 50’s or 60’s and you will find it is nothing like today’s version.
As for the bottles in this story, they are not “bootleg”, despite the name. They are a blended scotch from, you guessed it, Scotland. Vintage Old Smuggler fetches a very high price, even in Scotland. If in good condition, these should fetch over $1,000/bottle.
“The age of whiskey only counts when it is the barrel. After it is bottled, age doesn’t matter one whit.”
Is that also true of wine?