In the early episodes, set in the 1950s, a pin-up photo of Raquel Welch can been seen. Welch rose to stardom in 1966.
Throughout the series which is set in the period 1950 to 1966 agent Tanner and several minor characters wear long hair covering their ears. This was unheard of for males in that period but became popular in the 1970s when the series was produced.