Amazing piece! I wannit I wannit I wannit I wannit.
Note the spike is of squarish section like a tang. Squared or rounded spikes are common on sickle type tools, usually at the tip, and I wonder if they are not a sharpening aid, for resting the blade or chunking it into the ground or stump for field sharpening. Others speculate such tips keep the blade from striking hidden rocks and such. A mystery, and compare the pinegas head hunting axe of Luzon with its square0section backspike?......