The William Schollhorn Co. (New Haven, CN) - Incorporated in 1891 as a "Hardware Manufacturer." In 1896 they filed a patent infringement suit against the Bridgeport Hardware Manufacturing Co. regarding shear and punch designs. In 1899 they sold the hand shear part of their business to The National Shear Company. They appear to have remained in business until at least the late 1940's.
UPDATE: See the comment and announcement posted below. The company was acquired in 1948 by Sargent and Company of New Haven, CT.
Sub Brands / Trade Names / Trademarks