Original door trade vintage catalog for THE R. C. MAHON COMPANY of Detroit, MI. Manufacturers of Rolling Steel Doors, Grilles, and Shutters. Made with specially designed interlocking slats from copper bearing electro-galvanized steel, aluminum or bronze. Installed in the Pere Marquette Freight Terminal. Intermediate hinged posts, wind locks, weather tight. Disbound from a large 1941 construction materials book, this unique old five page technical specifications brochure would display beautifully matted and framed. A marvelous addition to your retro industrial architecture library. Pages are detached and contain a small amount of residual glue on edge. Slight damp stain on corner tip.