I only have Heritage Quest to use at home. I found the family on the 1870 census by using HQ. Have you used the Advance Search feature?
I used what I found on the 1880 census. Click on advance search. I put in surname only, McCracken, you never know what abreviations the enumerators may use, or even just an initial. Then - Census Year 1870; State [in this case I just used ALL as I had tried several states without results]; leave out county; Age 21-30 [Henry "should" be about 29]; Sex male; Race white; Birth Place Alabama. And, that's how I found H.A., wife and son Willis in Gibson Co, TN.
With that advance search you can play around with what you put in, if no success, try various combinations of information. Men often do not age 10 years between censuses. Location of birth may vary. As you can see Willis said he ws born in MS, but we find he actually was born in TN. So, as an adult Willis may have told an enumerator he was born in MS.
Does obit for Willis give names of any survivors? They would be the ones who have his paintings, or know what happened to them.