I recently was in contact with someone who shared their research on Frederick Jergen Wessel (Henry and Marie's son and Henry Frederick's brother).
This person was given a letter some years before from an aunt who found Henry and Marie and family in the 1880 federal census. This is what I was given:
1880 Census for Elk River Township, Clinton County, Iowa
Listed Henry Wessel, age 56, born in Prussia, farmer Mary Wessel, wife, born in Prussia Henry, son, age 24, born in Illinois Fred, son, age 14, born in Illinois Addie, daughter, age 9, born in Illinois George, son, age 8, born in Iowa Ella, daughter, age 6, born in Iowa Anna, daughter, age 3, born in Iowa
also living with them were: William Lampe, son-in-law, age 24, born in Iowa Mary Lampe, daughter, age 22, born in Illinois Henry Lampe, grandson, age 1, born in Iowa
Is this new information for you? It was for me. Have you turned up anything new on Henry and Marie? I look forward to hearing from you.