they are basically a wooden plank with a grip and grooves along the sides of where the blade would go, and in the grooves you put Flint for the aztec sword, or shark teeth for the Hawaiian sword.
while the flint is exceptionally good at slicing, dicing, and chicken-fried-ricing most anything with flesh (hence the very exceptional damage), it breaks incredibly easy. all it takes is one blocked blow, or one wrong swing to break the flint (hence the low durability).
with the Hawaiian sword, the shark teeth are very good at shredding flesh and are designed to break off in the body to cause extra damage (could be simulated with bleeding effect).
so, what do you think?
it would fit the theme and act as a melee parallel to the sawn off shotty, giving better damage per strike but lacking in general handling.