Have you tried familysearch.com <FamilySearch.org? They have indexed many of the German church records. I think you need to be a member of the church to see their digital copies, but a search of the index can give you some good clues on where to look in Archion or Matricula.
I have some ancestors named Deter in Versmold, but they are probably not related to your Deters.
Cheryl Viering