Based on this photographic proof, I’d say that actors Red Buttons and Joseph Gordon-Levitt were separated at birth.
Separated at Birth? (Red Buttons and Joseph Gordon-Levitt) – The Man in the Gray Flannel Suit
Separated at Birth? (Red Buttons and Joseph Gordon-Levitt) – The Man in the Gray Flannel Suit
Separated at Birth? (Red Buttons and Joseph Gordon-Levitt) – The Man in the Gray Flannel Suit
Separated at Birth? (Red Buttons and Joseph Gordon-Levitt) – The Man in the Gray Flannel Suit
Separated at Birth? (Red Buttons and Joseph Gordon-Levitt) – The Man in the Gray Flannel Suit
Separated at Birth? (Red Buttons and Joseph Gordon-Levitt) – The Man in the Gray Flannel Suit
Separated at Birth? (Red Buttons and Joseph Gordon-Levitt) – The Man in the Gray Flannel Suit
Separated at Birth? (Red Buttons and Joseph Gordon-Levitt) – The Man in the Gray Flannel Suit