It's amazing how the brain can recall something from 50 plus years ago.
“I definitely remember the Hollywood Squares. Lily Tomlin looked young!”
Hollywood Squares, along with the Art Fleming version of Jeopardy, the 1963 to 1969 version of Match Game, and numerous others was the victim of the great purge allegedly ordered by a woman who was the daytime program director at NBC and in about 1975 allegedly gave the order to destroy the vast collection of videotapes and films of game shows and soap operas (going back to the mid 1950s) in their archive at that time.
As a result, Hollywood Squares shows from the late ‘60s to about 1975 are fairly rare IIRC and are sought after in the TV collection market.