Faithful RemnantI managed to locate the couple I promised but their reply really sums up what you already know by personal experience:
"Thank you for writing. Estonia is a very atheistic country. We and our Latvian brothers have researched the situation there and have not found any Reformed churches.
I wish that I could be of help, but don't have any suggestions."
I pray the Lord will be thy confidence and help-nothing is too hard for HIM.