Here are 3 Fixed blades, from 8 1/2" to 10 1/2", 2 USA, Dexter & R. Murphy, and 1 German, F. Herder. The Dexter has the round handle shaved to flat on the sides, rather odd. I think all 3 have a special purpose in some industrial or agricultural application. The Herder might however be a kitchen food prep knife ? My guess for the Murphy is leather work, but exactly what aspect i have no idea, and it's only a guess. If you know these blade profiles please post. kj
Dexter/Russell still makes all these knives, and probably Herder as well.
I have some much older ones in a box, an assortment of three different shoe knives used for cutting leather in the making of shoes of course. They are also used today for cutting, splicing, trimming, etc. rubber and plastic, in fact with an 8" blade the top knife in your first picture is used for cutting rubber and is called a rubber knife but it can be used for several different materials.
i ordered some murphy knives several years ago-they are still in business-studied up on them a bit-you got it right-they list this knife as a shoe knife-they make some industrial knives-commercial knives for opening shellfish,ect....-the others look like work knives for a specific purpose---by the way murphy made all herders fixed blade knives....Kendal at bladematrix sells murphy knives-they make a neat Canadian style skinner-1095 steel..youtube used to have factory tour...
KJ, suffice it to say that they are used in industrial settings, I used them in a boot making plant in ' 64, in the late 60's I worked in none wovens fabrics and we used them there, but we call them shoe knives, but they could be used for lots of things, I've cut a lot of cardboard with them, very good carbon steel back in the day took a good edge and held it.
if you like old school knives try some murphy knives-all but fish knives are regular old 1095 steel like your grannies 'old hickory' kitchen knife..and kabars,ect. the Canadian style knives are ugly to me but feel very good in the hand..