Age and Valuation of Johnnie Walker Black

[DWK]

Hi,

We have unearthed a bottle of Johnnie Walker Black Label that we think is from the 1960s. We wondered if we could pinpoint its age and get an idea of its worth.

The diagonal label says 70 proof 75.7 Cl 26 2/3 FL OZS.

There is also a number on the back of the label that can be read through the bottle: 77-1555-15

Any help is greatly appreciated.

Happy Christmas!