Strange brace on 36 pickup bed AGAIN

[Lawson Cox]

ODD BRACE ON 36 BED.jpg

I got no response to previous post about this strange feature on a couple of 36 pickup bed sides so I thought I would re-post with a picture. This is in fact a basically original 36 Ford pickup, NOT A 37. Can anyone enlighten me about how this brace came to be on a 36 PU? I have pictures of two different pickups with this brace. One May 36 and the other very near the end of 36 production. Darn if old Henry can't keep us mystified. lol