A bit more photographic evidence--the old score displays were still present during at least the first week that Mary Tyler Moore was a guest (May 24-28, 1971; she appeared again the week of September 6, on both occasions with Jack Cassidy):
http://tinyurl.com/3jok4spBy the way, does anyone recognize the celebrities in the 4-second clip of Password in ABC's fall '74 promo? (It starts at 2:22):
http://tinyurl.com/6y6prgaThe little zero, I presume, indicated how many games a team had won in the best-2-of-3 matches (as opposed to the one-loss-and-out format in use at the time of the Klugman-Somers episode).