Need help. Old button? Old coins?

[crossfire631]

Found these at same site few years ago. Site very old dates back to colonial era. Thinking larger one is maybe a button due to small tab on back?
Two smaller I’m guessing coins but can’t identify. Any help would be appreciated. Thanks!

 

[Professor of Engineering]

Nice finds! Perhaps some clearer and front/reverse (no angle) photos will help in the ID.