This ‘De Luxe’ stainless table knife was probably part of a cutlery canteen.    Such canteens, with presentation cases in wood and with items marked Norman Hirst & Co, occasionally appear at auction.   They are usually dated 1920s-1930s,which seems about right.   They are marked ‘Sheffield’, though Norman Hirst & Co was not listed as a merchant or cutlery manufacturer in local directories.   Hirst presumably was based elsewhere, though a search of business and newspaper data bases has failed to find any mention of the enterprise.   
One possibility it that the original name was not Hirst, but ‘Hirsch’.    Several Hirsch family members settled in London before the First World War.   They were German Jews, some of whom became merchants, and some of whom changed their name to Hirst.   It is interesting to note that a London directory in 1901 listed Norman Hirsch & Co, merchants, wholesale fancy stationers, and importers of fancy goods at Finsbury Pavement.   No further information on this firm has been found, but the Hirsch link offers a promising line for research.