In 1910, New Hampton, Census there is August Diekmann, age 46, wife Augusta, age 42 (death records indicate b. 1866, d. 1928, buried St Johns Cemetery, New Hampton, surname spelled Dickman), Fred age 13, Albert 11, Augusta 9, Minnie 3. I found August and wife in 1920 census with only one dau which I can't read, age 12.
In 1910, Avery Grimsby, age 39 (death records indicate d. 1914, buried in lot 446, Graceland Cemetery, also Conrad Grimsby and his wife), wife Minnie 43, Carl 12, ???, 11, Walker, 8, Eva 8, Earl 6, and Mary 5.
In 1920 in Chickasaw, Walter is 18 and living with mother Minnie, brother Earl, 16, Mary 15 (can't tell relationship).
In 1930 Walker and Augusta are in Minneapolis, with children Emerson and Agatha, possibly twins. Also in Minneapolis is brother Carl and mother Minnie is living with him.
Walker d. in Hennepin County and is buried in Pleasant View Cemetery, Burnsville Township, Dakota County, Minnesota. Notes are that his mother's maiden name is MACKE and that he married Augusta M. 20 Aug 1924.
Hope this helps in continuing your search.
Sincerely,
Mike Peterson