I have the same relationship with my barber!

Knives of that style were made by many Sheffield cutlery firms, both before and after WW2. However, between 1939 and 1945, Sheffield cutlers were only allowed to do 'War Work' making knives for the military. Because of steel shortages, and the fact that cutlers were a 'reserved occupation', this was very strictly enforced, and if any private purchase knives were produced during this period, they probably wouldn't have had a maker's mark. It's possible that the U.S. military were allowed to contract knives from Sheffield cutlers, but I don't have any information about that. However, there were large numbers of G.I.s stationed in and around Sheffield before 'The Big Push', and I dare say, knives produced before 1939 would have been a popular trade item