Very interesting unidentified dagger from the 1930s, probably GIL Gioventu Italiana del Littorio.

A very interesting and virtually unique dagger/knife resembling the uncertified knives proposed for the GIL Academies, but with the characteristic of being made in three pieces, with a wooden hilt guard and an eagle's head body.
This knife resembles the one photographed on page 404 of Cesare Calamndrei's book "Del Pugnale il Fiero Lampo" (The Blade of the Fierce Lamp), with the difference that the one in the book, which I found 40 years ago, is smooth and lacks the "feathers."
It's likely that they are little more than prototypes proposed by some company and rejected. Of these knives with "feathers," this is currently the only one known.