original hard to find c. 1920's oversized american antique single-sided chicago commercial store door flush mount informational sign fabricated by the burdick enamel sign co., chicago, il. the cold-rolled steel or iron sign contains a highly desirable cobalt blue porcelain enameled finish with bold white lettering. surface wear evident along the edges. the "push" door sign contains four pre-drilled holes for mounting purposes. measures 12 x 4 inches.