I think there are a few knive cranks on this forum who will know a lot about this. My impression, for what it is worth - not so much - is that there were many custom knife makers in the 19th C both here and in England but by WWI the factories like Marbles had pretty much pushed them out. There were a few still around in the interwar period but the big boom in custom knifemaking did not start until WWII with the likes of Randall, which because of demand became practically a production operation. In the last half century we have had a tremendous proliferation of custom makers, paralleling custom guns, and the development of a lot of fancy work - again like the guns. The few custom knives in the interwar period were plain and practical, made for use not for BS.