I do not have a connection to Black Hawk County, but I have a Scherffius in 1866 Houston, Texas. A Henry scherffius married Emily Branard. He apparently went into business with his wife's brother, George A. Branard in Houston. The two names appear in an ad in the Dallas Herald newspaper Nov. 3, 1866. I am related to George A. Branard. The 1870 Harris County Census shows Henry, Emily, and a 2 year old, George H., living in Houston, Tx. It also shows Henry was born in Prussia. He was shown to be 31 in 1870. Are any of these names in your ancestry line?