This maker of this pruning knife is not easy to identify, as no cutlery manufacturer named ‘William Mills’ has been found in directories.  However, it may have been marketed by William Mills & Co (Sheffield) Ltd.  This was a manufacturer of spades, shovels, and forks, which was launched at Handsworth, near Sheffield, in the late nineteenth century.  It occupied Woodhouse Mill.  William Mills & Co was incorporated in 1949, when Edmund H. Mills was chairman.  If this knife was sold by Mills’, it would have been ‘bought in’ from a Sheffield cutlery manufacturer and offered alongside other stainless steel garden tools.  In 1973, when the Mills’ company was making losses, it was purchased by Stanley Tools.

See also Geoffrey Tweedale, Directory of Sheffield Tool Manufacturers 1740-2018 (2019).