Anecdote: (if I remember the dates correctly)
I was aware that Jacky had a new cognac.
When I visited him in March 2018, I received the answer that the cognac was not "ready" yet. He still needed 3 months.
Next visit : June 2018 I received the answer:
Not ready yet. A marriage takes time. What difference does a few months make with a 50 year old cognac?
In September 2018 I bought the very first bottle.
It's a blend :
10% : 1958-1959
50% : 1965
40% : 1970-1975
At our last visit, i had the impression that the Souvenir Imperial was better than the first bottle.