For anyone who's interested, Getty Images has an extensive library of photos from the ABC Password. There are a number of nice full-set shots (mostly 1971-74 but also some from the revised formats), as well as various candid moments for which we may never see the corresponding videotape.
During the first week, Allen was still wearing horn-rimmed glasses and the score displays were similar to what was used in the CBS series. By the time Henry Fonda played during the week of September 20, 1971, the score was displayed in eggcrate format (was Password the first G-T use of that display?). And there's the big 2000-episode sign from early 1972 (shooting out of a cannon), as well as the huge Emmy of 1974. The week of October 14, 1974 has a lot of coverage; Carol Burnett and Vicki Lawrence played against stars such as Rock Hudson.
All can be seen at
www.gettyimages.com; be sure to select "editorial images" when searching for Password. The dates provided will not necessarily be taping or air dates.