An update I found on that adjustable wrench from Diamond Calk Horseshoe co...
"The Diamond Calk Horseshoe Company was founded in 1908 by Otto Swanstrom, a blacksmith operating in Duluth, Minnesota. As the name suggests, the company was formed to make calks and horseshoes, and their initial product was a patented insertable calk for horseshoes. (A calk is a gripping bit on a horseshoe, added for better traction on ice or slippery surfaces.)
Diamond was very successful in their calk and horseshoe business, but as the tractor and automobile reduced the need for horses and horseshoes, the company turned its forging skills to the production of adjustable wrenches.
An example of an early Diamond adjustable wrench can be seen in the illustration, part of an advertisement placed in a 1922 issue of The Horseshoer's Magazine.
In the mid 1920s Diamond was selected as the supplier of adjustable wrenches for the Motor Tool Specialty Company, the distributor organization for the Snap-On Wrench Company. This must have been both a high honor and a tremendous boost for their sales efforts, as Diamond brand wrenches were shown together with the Snap-On sockets and drive tools. Snap-On continued to offer Diamond brand wrenches in its catalogs until the late 1930s, and when its own Blue Point brand adjustable wrenches were introduced, Diamond appears to have continued as the contract manufacturer."
So Diamond Calk has a connection with Snap-On Tools. I'd have never guessed.....
Thomas