Hmmm...……...so they are from the Congo, and the other clue is that they 'seem' to have a certain age. As the quiz seems to be 'essay' rather than multiple choice
I can answer question item number two...…..this is a 'trombash' from the Mangbetu people of Congo (now Zaire). Rather than being a weapon, it is primarily used as currency, but more as a status oriented symbol of rank. If I recall, the holes have to do with the rank of the individual.
The others I do not have African references handy, but do seem to be Congo.
As to age, it is always safe to say 19th c. but many of these were collected into 20th.
Very attractive examples and nice Congo grouping.