I was very happy to see the 'NCIS' episode "Meat Puzzle" although I didn't know it when it started.
"What did Ducky look like when he was young?"
Kuryakin was a Russian agent working for the United Network Command for Law Enforcement (an international organization that might be connected to the United Nations.) But in the years between the end of 'The Man From U.N.C.L.E.' and the reunion movie fifteen years later, Ilya became a world famous fashion designer.
And that's the life of Ilya Kuryakin which Gibbs was familiar with. (He probably had to shell out the big bucks for several Kuryakin originals in a futile effort to placate one of his ex-wives.)