Swap Meet Gauge Find Identification

At the Goodguys SW swap meet I found this little gem in a $1 box. It will probably end up in a sculpture but I'd still like to know where it came from. Any ideas?





(click for a larger image)

The lettering is pretty much gone but I can see that it was made in Lacrosse Wisconsin and it goes from 20-0-20. There are no marks or stampings on it anywhere. Its about 2" across.

Thanks!
Ryland

 

From the pic it looks like an amp gauge but whats different is the charge and discharge are backwards than most .