I got this from my father in law's yard sale, as I thought it looked cool and would fit nicely with some other antiques I have. I am not sure where he got it, but he was in the Navy so I am guess that was the appeal it had to him. It actually works, and there are instructions printed on the back. It was made around 1940, or within a year or two of that since that is when the contract was issued. The plackard shown is on the left side of the meter.