A couple of years ago I bought 2 tins off ebay that were 19 years old. I haven't actually tried the new as they don't sell it in the UK anymore? but a tobacco buddy (thanks Paulie?) sent me a 50g pouch to try. It's currently in a jar waiting to be smoked but I haven't had a bowl yet as I like to give it 6 months in the jar first.
Here's a side by side picture of the two. Aged is on the bottom. Even with my arse backwards photography skills you can still see the aged has gone very black.