As has been stated, macassar ebony is significantly harder and more resistant to denting. You really need a much larger piece of wood to showcase the beautiful grain of macassar, the small scales on the Mnandi won't do it justice. The color of the scales on the mnandi could be blond, very dark, or a combination, depending on the piece that was used to make the scales. African blackwood will usually be a more uniform black or dark brown. If the macassar scales are from a dark portion of wood, it would be very difficult to tell apart from blackwood from a distance. African blackwood is a rosewood and is oily, while macassar, being an ebony, has very little oil.
Macassar is one of my favorite woods, and I would take it over blackwood if I had the choice.