There’s one episode where Kate asks Gibbs “What did Ducky look like when he was younger?”, and he answers: “Ilya Kuryakin”. Ilya Kuryakin is actually the name of the character David McCallum played on the hit 60s show “The Man from U.N.C.L.E.”.
Sapphire and steel. Joanna Lumley and David McCallum. Great show! Joanna Lumley was my favourite female on telly when I was a kid and I loved David McCallum from the covers of the Man from Uncle books I used to read even though I never actually saw an episode until I was in my 20's!