We have among our family ancestors, Martin MENGELT and Ursula RUEDY, through their daughter, Manga MENGELT and her husband, Charles MARKS.
I've seen some possibly conflicting information concerning Martin and Ursula, but a Martin Mengelt who I suspect is "our" Martin Mengelt appears as a 50-year old head of household in the 1870 U.S. Census in the town of Honey Creek [Honeycreek], Sauk County, Wisconsin. The woman of the household is listed as 47-year old Mary Mengelt.
The Mengelt folks above all appear to have emigrated from Switzerland.
Might any of these folks tie into your lines? Thanks!