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.
Oh, I will take an vintage bottle of Old Grand Dad, bottled in bond, any day. If you need an address, I would be more than happy to forward one to you. ;^)
In common speech “bootleg” just meant any alcohol illegally distributed and sold at the time. Plenty of “bootleg” whiskey was just smuggled in from Canada. Not all bootleg liquor was bathtub gin. I’ve drank plenty of fine moonshine and it is also considered “bootleg”.