The handsets didn't say Bell System until about 1969 when they added the "Bell System Property Not for Sale" to them. Your handsets are correct for your phones. Later on in the 1980s they changed it again to a small Bell logo and Western Electric and they took away the "not for sale" part, because they were for sale by that time.
Oh, and the historic anniversary is the bombing of Pearl Harbor by the Japanese on December 7, 1941. A date that will live in infamy, as Roosevelt said. Dennis is still looking for phone parts dated 11-22-63, another infamous date.