
This brass object measures 25.3mm in diameter and weighs 5.49 grams. It was struck by GREENDUCK CO. CHICAGO as shown on the reverse top. The bottom has two hallmarks, the left looks like a spoked wheel in an oval and the right looks like the letters NPIU in a shield. It appears there was a small clip soldered to the center.

Any idea what this is? Maybe a Civilian Conservation Corps badge of the FDR era?
Thanks for any info.