Bava Metzia 25: Dropped Coins

A new mishnah - with a list of when a finder has to proclaim and declare the found item(s), so that the original owner can come forward. With debates over whether an item has a siman (demarcating the item) is near an item that doesn't have the mark. How did they settle these relatively ordinary cases? One example being a basket with or without a rim. Also, when one drops coins, and they are in a small (very small) organized pile of coins - vs. a scattered pile of kinds. Plus, a whole lot of conditions and configurations of the coins to be required to proclaim the find in case the original owner comes forward. Plus, one more mishnah and a question about the halakhic expertise of regular people.