Sister Boniface's microscope is always missing its eyepiece. She is looking down an empty tube.
Sister Boniface appears to be riding a Piaggio Vespa PX. The series takes place in the early 1960s, but the PX was not introduced until 1977.
Telephones of this era did not have a removable white plastic lead/plug, they were dark plastic or cotton wrapped, hardwired into the wall.