I sent Daves49 a picture of the complete drivers side rear brake set-up with the emergency brake cable attaced the the lever and the spreader bar attached between the brake shoes at the top. They don't sell spreader bars like this at the store that for sure.
I lucked out and pulled this one off a junker truck a guy down the street gave me. He was actually hauling off a 54 GMC deluxe cab on a 1950 AD frame.