Sounds to me like the difference is Huck brakes(1950) and Bendix brakes(about 1952 I think). Huck brakes float and pivot in the center of each shoe. Bendix pivot at the top and are pushed by the cylinder also at the top. The adjuster is at the bottom. Huck system has links from each shoe to a center pivot towards the bottom. They are quite different. Easy way to tell one from the other, is the diameter of the wheel cylinder. Big is Huck. Smaller is Bendix. The spring anchors for Bendix are in the center of the shoe. They just hold the shoe against the backing plate and allow the shoe to float. The anchor for Huck is very different. The Drums are different. So there is a lot to look at. Bendix have a leading and a trailing shoe. One is shorter(the trailing shoe) the other is longer(the leading shoe) Think, wedge. As the drum rotates one shoe is wedged tighter by the motion of the drum. The other shoe is just pressed by the cylinder with the rotation. I know it sounds strange, but just look and imagine the motion.
