A few hints ... may i ?
Hercules is one of the most important Brazilian cutlers, specialized in knife cases and cutler components, created around 1930-40, from a group originated by a few German imigrant cutler masters. They (Hercules) pioneered inox steel, with marks like Platinox and Gelodur.
I wonder if these recurrent pattern gaucho knives were made only for gift purposes, their main business being table cutlery.