South Beloit, Il is pretty darn close to Wisconsin.
This is my guess... as I had no luck either..... Looks homemade to me, not mass produced. I'm betting that they made that in house at the factory to spray their driveway, or lawn or something.... and put a sticker on the tank. I'm willing to bet it is one of a kind.
I mean, the pipe that holds the wand is open on top. Not a very good design. The front wheel is attached to the tongue, and it has 3 wheels. 3 HARD, narrow wheels. You wouldn't want to use that in a yard if it was full of water. I'm sticking with someone made it and put the stickers on the tank. Or used a tank that had the stickers on it.