Thanks for all the input. From our good friends at Old Bicycle...
What you actually have there is a 2-speed Bendix hub from the 1950s, which in fact is older than the bicycle. Bendix called the hub The Multispeed and lots of them were sold in the 1950s. They changed this design at the end of the 50s and went to the Bendix Automatic (a non-cable-operated 2-speed).