Have you tried city directories? I used city directories to follow my elusive Kinnaugh ancestors from New York City to Hoboken, NJ. They helped me identify a period of a few years in which my great-great-grandfather, John Kinnaugh, died and provided me with the address at which they were living during the 1880 census. Also, have you looked under H? My Kinnaugh ancestors should have been in the Soundex index for the 1880 census: they had a 9-year old son when the census was taken. When I found them, using the address from the city directory, I discovered that the K in Kinnaugh looked like an H, not a K.