Since its first airing in 1961, "The Avengers "has become one of the most enduringly popular series in the history of television-reaching its height in the episodes where Patick Macnee starred as the impeccable John Steed opposite Diana Rigg's strong, sensual Mrs. Peel. The Avengers' world was always full of upper-class derring-do, a place of distinctly elegant high jinks-all portrayed with tongue firmly in cheek. Now, television historian Dave Rogers...