Brillion Iron Works Display Rack

I know almost nothing about the brand, the age of the rack, or what was displayed on it. I thought at first it might have been for brochures, but it seems that they would fall straight through. Any suggestions on its possible uses would be welcome. At the moment I am using it to display some of my smaller signs.

Also, would anyone know a method of cleaning off the rust at the bottom of the sign? It would look much more handsome without it.