I went back and looked at the 1850, 1860 and 1870 censuses.This is how I transcribe them.
1850 Census - United States, State of Iowa, Polk County, Fort Des Moines, Page 22 Line 35 189 199 Harvey Murdock33MChairmakerOhio Catherine~28FOhio Susanna~10FOhio Melinda~6FOhio Addison~4MOhio Andrew~1MOhio
1860 Census - United States, State of Ohio, County of Highland, Paint Township, Page 217
Line 6327326 Harvey Murdock41MBlacksmith500Ohio Hester~34FVirginia Melinda~16FOhio Addison~13MOhio Andrew~11 MOhio
1870 Census - United States, State of Ohio, Highland County, Paint Township, Page 278(b) Line 26185192 Murdock, Harrison50MWMiller70002000Ohio ~H Ester47FWKeeping HouseVirginia ~Addison C.23MWLaborer100Ohio ~Andrew M.21 MWLaborerOhio ~Melidda22FWHelps MotherOhio ~Daniel H.15MWWorks in the MillOhio ~Frank7MWAt SchoolOhio ~Eva3FWOhio
In the 1880 census Esther Murdock is living with her parents Joseph (I believe his full name was Aaron Joseph Dwyer or Joseph Aaron Dwyer) and Abigail Dwyer and Esther's two children Frank (I believe his full name was Aaron Frank. Murdock) and Eva.
I did not find a Harvey, Jr. in the census for 1850, 1860, 1870 or 1880.I looked under Andrew, John, Harrison, Addison and Harvey.
I can't explain the guardianship unless these were children of another family member.
Why do you think Harvey's family is listed under Harrison in the 1870 census?Do you think there is a typo on Harvey's date of death - that it should be 1868 instead?
John's son, James'children's names changed in the 1880 census - strange.