Both Western Electric and Automatic Electric candlestick telephones are shown. These were competing manufacturing companies that would not be seen in the same geographical area. The "Bell System" would use only Western Electric telephones connected to their telephone lines. Independent telephone companies would use Automatic Electric and many other manufacturers telephones connected to their telephone lines.
Al Capone's son, Sonny, is portrayed as being entirely deaf at the age of two. In real life Sonny contracted an infection that left him only partially deaf and only at age seven. However, this series is intended to be fictional, not based on real life events. Factual inaccuracies are therefore not considered goofs.