Nice set of coins. Remember, no matter what an app says or who you talk to, your coins are worth what someone that day is willing to pay for them. It is correct that a "no date" coin is worth face value with a few exceptions. The gold coin is a great find. Any time you find a hole in a coin it ruins it and, in some cases, makes it worth literally nothing unless some one wants it for jewelry purposes. Always many exceptions out there.
Jedi said it best. I forget about the gold coin ,it has value if for nothing else the gold. I don't know how the coin app gives a value for the buffalos with the dates worn off. The Indian head could have some if it has an s mint mark. We need to see the back of the coin for further analysis.