The same blue panel van is used in several Barnaby episodes and other QM productions such as The Streets of San Francisco.
While Barnaby (Buddy Ebsen) is using the Greek typewriter Betty (Lee Meriwether) refers to Pandora's Box, which is an artifact in Greek mythology which, when opened, released physical and emotional curses upon mankind.
This episode aired on guest star Carleton Young's 68th birthday (born October 21, 1905).