I love the mystery of genealogy but these parts are frustrating! I've been looking up Swiss and Mennonite history and it helps a bit. (Can you believe I started this to find my Jewish ancestors and ended up with a tree full of Mennonites, too?!)

Did any of your Kreigers go to the US or Russia at some point? Seems like a LOT of Mennonites went to south Russia in the 1800s-the 'Germans from Russia'board has some good links. Also I've found these books to be very helpful for finding names (most are people that went to the US, but you can find older names too):

Historic background and annals of the Swiss and German pioneer settlers (on Google books)

A collection of thirty thousand names of German, Swiss, Dutch, French, Portuguese and other immigrants in Pennsylvania (on archive.org)