Hi Augie, I'm grabbing this opportunity to make some observations (from down-under) while the real experts are still asleep. Your 'square-pointed Royal Navy knife' by "Hunter Sheffield" is a real beauty. The "W↑D4" stamp indicates that it was supplied under a 'Military contract' rather than for the Royal Navy - the WD being the War Department. Examples are well documented by Ron Flook in his book “British & Commonwealth Military Knives" on pages 126, 127 and 128. Their use by the military, as indicated by the W↑D stamp, appears to have preceded the Boer War by some years as Flook (Plate 291 page 128) notes an example that is dated 1878 and tang stamped ‘DEANE & CO.’. The "out of service" stamping is uncommon and certainly adds value.
Knives stamped "Hunter Sheffield" are not uncommon, I have one "Hunter Sheffield" square-pointed Royal Navy knife but nowhere near the quality of yours, and also a couple of 'Boer War Jack Knives' similarly stamped, however it is difficult to know which of the four Sheffield cutlery manufacturers with "Hunter" in the name is the actual maker of these clasp knives. I favor "M. HUNTER & SON LTD" as they appear to have been in business around the time of manufacture of your knife. If you don't already have access to the online version of "Tweedale's Dictionary of Sheffield Cutlery Manufacturers" it can be accessed at https://hawleysheffieldknives.com/
Lawrie
Knives stamped "Hunter Sheffield" are not uncommon, I have one "Hunter Sheffield" square-pointed Royal Navy knife but nowhere near the quality of yours, and also a couple of 'Boer War Jack Knives' similarly stamped, however it is difficult to know which of the four Sheffield cutlery manufacturers with "Hunter" in the name is the actual maker of these clasp knives. I favor "M. HUNTER & SON LTD" as they appear to have been in business around the time of manufacture of your knife. If you don't already have access to the online version of "Tweedale's Dictionary of Sheffield Cutlery Manufacturers" it can be accessed at https://hawleysheffieldknives.com/
Lawrie