Maybe your brakes are missing the emergency brake levers that the cable hooks up to. These attach to the inside of the rear shoe. There is a hook at the bottom of them (for the cable to hook onto). Then there there is a rod that connects to the front shoe. Once the cable is tightened and pulls the lever, the rod causes the front shoe to press against the drum. This link has a picture of the lever (although the diagram is for a 1 ton the-1/2 ton one looks very similar. http://chevy.oldcarmanualproject.com/1929_54chevyparts/04/316.HTM. Look at 5.149 Lever and 5.150 Extension.

It's a small world, but I wouldn't want to paint it.