I don't think the Find A Grave memorial for Michael King is the same Michael King. The biography on that memorial says they live in Chatfield. Your 1875 MN Census shows them in the Hancock Township, Carver County, MN - 120 miles away.
This 1860 Census also shows them in the adjacent San Francisco Township, in Carver County.
This 1870 Census says Hancock Township, Carver County, MN.
This 1880 Census shows his wife and younger children in Hancock Township, Carver County, MN, and it says his wife is widowed.
So it appears that your Michael King died between 1875-1880, whereas the Michael King of the Find A Grave memorial lived until 1906. Also, the memorial alleges he had a son named Peter and one named Michael. Your Michael King did have a son named Michael, but none of the records we've discussed mention any other son at all who could be Peter. Also, the 1860 census shows Michael as a newborn and the FG Michael King's son Michael was born in October 1861, allegedly.
Obviously we don't know if the FG memorial is accurate or not (though it is better written than most) - but I think you have enough evidence to disregard the name Sloan, and to change Michael King's date of death.
This doesn't settle if Elenora is Nellie G - but it does remove an obstacle.