I'm sure the 1964 is counterfeit. If you could post clear photos of both sides of the entire coin it would be appreciated.
The 21 & 34-S are polished, many of the other coins have environmental damage, and that assumes that all the coins are genuine which we can’t do since we already know at least one isn’t. A set like this, I wouldn’t walk away, I’d run!
Have you checked the weights of these? Used a magnet? A lot of "sets" are being minted in China right now. All 100% fake, most not even silver.