I believe you've found him! The year of birth is right. My sister always insisted that his name was Ellertsen, not Ellison as in the 1920 Belmont census report.
It appears that Christen Gulbrandsen b. 1794 and Else Knudsdatter b. 1804 were his grandparents and Inger Pauline Christensen (not Christendatter?) b. 1834 was his mother. She must have married someone named Ellert for Emil to be Ellertsen.