Sunflower Ammunition Billboard

While I was exploring the perimiter of the Sunflower Armory Ammunition Plant, I ran into this billboard that had seen better days.

I could not tell if the billboard was part of the plant, or if it was put up after the plant was closed, but being close to the housing on the plant property, and the deterioration of the sign, I would imagine that it might have been used as part of the plant.