My wife has 3rd great-grandparents who were Brei's:

Joseph BREI, born Abt. 1823 in Fürth, Bayern (Bavaria), Germany. He married Anna BREI.

Anna BREI, born Abt. 1818 in Fürth, Bayern (Bavaria), Germany.

Roman Catholic Church records in Pittsburg indicate that Anna's maiden name was actually Brei.

The spelling of the name within my wife's family has several permutations that I have listed in the Surnames line.

I don't know if these are related to your Brey family, but if you see a connection, please contact me at my listed e-mail.