The rear wheel has a hub roller brake, a style of drum brake. It is operated by hand brake lever so you can backpedal freely.

This is an interesting choice, while it keeps the brakes protected from the elements, they are more likely to skid and overheat on long downhills. In the long run, these brakes should be nearly maintenance-free and only require some lubrication from time to time.

We start to fish out the brake cable, but it looks like it's riveted to the hub assembly, and will stay attached at that end.

So we loosen the bolt holding the hub to the frame and lift out the 16" wheel with its 28 spokes, 3-gear hub and roller brake, and its trailing brake cable...