Mount Olivet in Chicago does not have a cemetery office. They do have a kiosk at St. Casimir's west of Mount Olivet on 111th Street that you can do searches on. You can also pull up any burials at any of the Catholic Cemeteries of Chicago at any location that is equipped with a kiosk.
You can find which cemeteries have a kiosk here:http://www.catholiccemeterieschicago.org/selfServeKiosks.php
I have access to the kiosk daily so please let me know if I can help in any way.