What "period" are these found ?
I would say the basic lines and shapes of the knife being done here is similar stylistically to that of trade knives of the period.
While antler handle knives were no where near the norm, I have seen surviving originals. Folks say that original knives were never made from files, but still yet I see originals at shows that are new and have not been documented before.
Notice I said a knife that could be realistic to the period, not 100% historically accurate with provenance to a documented and catalogued original.
It is no different from the gun builder who may choose to create a composition gun, the fabled "Virginia", or the even more illusive pre rev war " transitional rifle.
The hobby is full of conjecture when it comes to rifles, fowlers, bags, horns, hawks and especially knives.