Your middle coin is a solidus/schilling of Sigismund III of Poland, minted in Riga, dated 1618 when Livonia was under Polish rule (the "18" is in the lower photo at about 5:00).
The coin on the right is issued under Swedish authority, as you can see GVST for Gustavus on the lower photo. Possibly it is this one:
https://en.numista.com/catalogue/pieces78795.htmlThere are experts here on Livonian coins who will be able to confirm this or provide a more accurate identification.
Edited by tdziemia
12/10/2018 3:24 pm