Incidentally, the Act which sent me down this rabbit hole was data 10 January 1842, and came into effect March 1842, so the reference to the County of Eden in the pro forma for a deed in this Act also pre-dated the official proclamation of Eden County!
I'm apparently not the first to wonder about Eden County. The "Manukau's Journey" site at Auckland Libraries cites an article "The Vanished County of Eden", published in 1971 by Dr GT Bloomfield of the University of Guelph. I will be getting a copy next time I go into the library.
#nzhistory #EdenCounty #legalhistory #AucklandLibraries