Another example is a distillery that never stopped using the old ways: BBC News. Label on back says Seal of assured Excellence Barton whiskey. It has never been opened. I wish Diageo and the like would see that - but unless it hits them in the wallet there will be no incentive for them to think about it. Most of that info can be looked up online so you can narrow your date range by looking up who was in charge when the tax stamp was used.
The Walkers created their primary marketing strategy in with advertisements featuring Browne's Striding Man, using the slogan, "Johnnie Walker:
How Can You Tell the Date of an Old Johnnie Walker Bottle?
If it reads: I'm certain that's part of it. Scotch Whisky: Those decanters are fairly common and depending on who made it, condition, actual age, etc. No surgeon generals warning. There is some numbers etched into the bottle, not sure how tobdecipher. How to Store Jack Daniels.