Offering compelling histories on these items isn't my strong suit, Woody, but I do like the names of the companies that were operating here in Detroit. Like Detroiters.....very direct, and to the point..... Like the Tuff-Hard Corporation.
They were awarded a patent on behalf of their President & GM, Frederick A. Endress for their heat-treating processes, that allowed them to compared their Moly Steel alloys as a functional equal to Tungsten.
They were located at the corner of Caniff Ave & Mound Rd, which would have been a very strategic location, particularly if they were doing business with Chrysler, as they would have been almost surrounded by their plants there at one point.