Help identifying year of J & B twenty 91 proof

[Unregistered]

Just received a bottle of J & B twenty year old blended scotch. It is 91 proof. 4/5 quart Imported by the paddington Corp. Bottle has imprinted on it, "federal law forbids sale or reuse of this bottle"

I can post pics if necessary.

Any help identifying the year is much appreciated.

Thanks