need help on 68 swb stepside

[drew07]

Im redoing a 68 c10 step-side for a guy. i received the bed in parts, and now im not quite sure where a part goes. The "step" on the bed has 3 bolt holes on top that attach directly to the bottom of the bedside. but there is a brace that attaches to the actual "step". it has 2 bolt holes on top of the step and then it curves under the step to the inside of the bed side and im not sure if there is a bracket missing but i cant seem to figure out what this attaches to. any help, and pictures would be greatly appreciated. ill add pics of brace asap