I found this diagram of the Huck brake parts to be helpful when I was searching for my parking brake parts. The diagram is for a one-ton, but it will be a good representation of the parts.
One Ton Rear BrakeHere's a pic I took when I was trying to figure out where all the parking brake parts were located (Right Rear). Also, another diagram. Note the springs and lock pins (NSS Part of 5.043 Pin Unit) that secure the brake shoes to the backing plate. Yours appear to be missing and that would allow the entire assembly to shift when the PB is applied. You can see them installed in my pic.