Take a look at this, it's not a great photo but the only one I could find in a quick search. Top picture seems most clear. http://www.oldchevytrucks.com/blog/index.php/2010/02/1947-1955-optional-wide-running-boards/ I have seen one set of thes and wish I would have fabricated something like this for my truck. I think this is along the lines of what you are speaking.
