I THINK THE BLACK FINISH OCCURS DURING THE FORGEING PROCESS AND IS PREFERRED LEFT ON IN AFRICA. IN EUROPEAN FORGEING THIS FINISH IS POLISHED OFF AND PERHAPS NOT AS PROMENENT AS IN THE FORGEING PROCESS USED IN AFRICA. HOPEFULLY SOME OF THE BLACKSMITH MEMBERS CAN CORRECT ME IF I AM WRONG.
I WOULD LIGHTLY CLEAN THE BLADE (REMOVE ALL OF THE REDISH BROWN ACTIVE RUST) AND THEN OIL THE BLADE. GENTLY CLEAN THE HANDLE WITH WARM WATER AND TOOTH BRUSH THEN WIPE IT DRY AND THEN LET IT DRY COMPLEATLY AND THEN APPLY SOME LEMON OIL OR WAX. THE RESULT SHOULD BE QUITE PLEASING. OR YOU COULD JUST SEND THE DIRTY OLD THING TO ME AND I WILL BE GLAD TO HAVE IT RESIDE IN MY COLLECTION.