Steve,
there are a lot of places SCHLATT. GOV :: The Historic Gazetteer or Schlatt – Wikipedia
If you are really sure, that your Schlatt is in the Black Forest it could be today a part of the town of Bad Krotzingen, district Freiburg (Breisgau)
Cause this Schlatt is Baden you may use a mailing list http://list.genealogy.net/mm/listinfo/bawue-l Baden Württemberg
Do not forget names and facts.
Klaus Meyer