Hi Barbie,
I'm looking in the Salzgitter area too for my Flamme/Flemme family from the village of Steinlah. Braunchweig has the Lutheran church records, Hildesheim has the Catholic records of the family and I've been told to approach Goslar for migration documents for Steinlah residents in the 1860's. Possibly Hildesheim had responsibility for the migration documents?
Season's Greetings everybody 
Rena