The first ones are not coins or cowries at all. They may have been armor plates or some kind of decoration. I have a piece that has a bar like the ones seen here, sized about the size of a dime, that is pretty well cast like these here. It was advertised as "shield money," but I think it is more likely an armor panel. That explains why I have not seen coins like this before, because they are not coins.
With that being said, the other cowries are more likely to be genuine. I keep looking at them, and I keep failing to see indesputable proof that they are counterfeit. Send pictures to Bob Reis, Scott Semans, and/or Frank Robinson. They are far more expert in these than I am, and they should be able to give a more-certain answer.
You asked about value. If genuine, the cowries will easily bring $100-300 each in a retail setting. I would love to buy one of each from you, but I can only afford what would be a lowball offer compared to the figure above. You are better off contacting the dealers mentioned above.