YOUR OBSERVATIONS ARE ALL VALID AND IT IS A BEAUTIFUL ITEM. CONGRADULATIONS.
UNFORTUNATELY I KNOW VERY LITTLE IN THIS FIELD BUT WOULD GUESS IT IS A ITEM DENOTING THE STATUS OF THE PERSON WHO CARRIED IT. IT MAY HAVE HAD SOME CEREMONIAL OR CLAN OR TRIBAL MEANINGS AS WELL. I DON'T KNOW IF THE VULTURE WAS SIGNIFICENT IN ANY AFRICAN CULTURES BUT SUSPECT IT WAS AS IT HOLDS SIGNIFICENCE IN MANY OTHER CULTURES. AND IT DOES INDEED LOOK LIKE A VULTURE TO ME.
AS A WEAPON IT IS WEAKENED IN THE MIDDLE BY THE HOLE THRU THE VULTURE SO IF USED TO STRIKE IT WOULD PROBABLY BE USED EITHER AS A STAFF WEAPON HELD IN THE MIDDLE OR CHOKED UP TO ONE END OR THE OTHER FOR A STRIKE OR JAB. EBONY IS VERY STRONG SO JABBING OR POKEING WITH EITHER END WOULD NOT HAVE RISKED BREAKING IT WHERE A HEAVY STRIKE HOLDING THE SMALL END WOULD.