Useful Telephoning Information:
Number for Perry's Office: MA 5-1190 (say this, "Madison five, one one nine oh.")
Number for Paul's Office: CR 9-7441 (say this, "Crestview nine, seven four four one.")
Number for Della Street: HO 2-1799 (say this, "Hollywood two, one seven nine nine.")
...And note that after business hours Perry's office number transfers to the Paul Drake Detective Agency's exchange. If you have interest in investigating telephone exchanges further, have a look at The Telephone EXchange Name Project.