You can clearly see a modern parked Mercedes at the end of the street in the of the street. (Around 25 seconds, when the car parks at the front of the house)
Outside the Coroners' Court at the Inquest, the sign is displayed without an apostrophe. This is a modern day 'simplification' and is unlikely to have been portrayed that way in the generic time period 1920s to 50s the film is set in.