I looked for the connecting bolt for a long time, finally just made my own. used pic of original for a guide. front panels were sheet metal probably 16/18/20 gauge
I see you used slotted screws and square nuts to hold together the stakes. Is that based off an original or creative license?
I just assumed they would be riveted
original steel post were riveted to the wood slats but from the small remaining post I had they were drilled with just what I have done! YOU do what you want