Steinkjer and Egge were separated from Stod clerical district in 1868. So finding records under books for Stod would seem right.
Martinius/Mortinius would be a name easily adapted to the more American Martin. Many emigrants adapted their names to Americanize. Ove would be a given name that probably didn't adapt easily and could be ignored in the new country.
I think you have found the correct person.
This is probably the family in the 1865 Norwegian census.http://digitalarkivet.uib.no/cgi-win/webcens.exe?slag=visbas...
They are residing on a subfarm then called Hælenbakken and his father is only a tenant farmer.