Individual found on 1880 Census for W. Conoquenessing Twp, Butler Co, PA
#146: Joseph LUTZ, age 31, Laborer
Lydia, age 35, wife
Jacob, age ? - either 10 or 14, son
Elizabeth, age 9, daughter
John, age 8, son
Rosanna, age 6, daughter
Jesse, age 3, son
Madeline, age 1, daughter

This John would have then been born in 1842-43, which is the right year to be the John LUTZ we are looking for.