The small hole in the tab at each end of the stamped-brass object in combination with the large U-shaped cut-out in the object's lower part suggests it is a suspenders-strap buckle, whose "tongue" broke off from the U-shaped cut-out's bottom. To more clearly see what I'm talking about, here's a photo of a suspender's-strap buckle with U-shaped cut-out and tongue. Pull the tongue downward until it tears off, and you'll see something very similat to the lower part of Collector01's stamped-brass object.