Although the digital copy is only a portion of the letter, it is the portion bearing Russell's signature. In fact, the signature is secretarial. Many copies of the letter were signed and sent to well-wishers who congratulated Russell on his role in the Cuban Missile Crisis. the typed carbon of the letter is at record 30905.

The signature on the left goes is from Russell's letter to Graham Greene, record 132433, which was offered for sale at the same time by Arenburg Auctions (https://www.invaluable.com/auction-lot/two-typed-letters-autogr-signature-220-c-fb140b1871).