McRae-Roberts Brass Mfg moved to Detroit in 1894. W. H. Roberts apparently withdrew from the company, forming his own 1906, and building the location above on Fort Street. An addition in 1916 more than doubled the size of the plant, adding a new foundry, larger machine shops, and new offices.
Roberts Brass was an earlier supplier to the automobile industry, as well as making "high grade brass goods for steam, water, and gasoline engines… motor priming cups, gasoline feed cocks, drain cocks, water gauges," to list just a few.
According to the folks at the DetroitYes! Forums, the building was in use as recently as a few years ago, but is now inactive. Today it is empty, aside from rusted barrels and cans of chemicals.