Here is a Shipp family living in Caddo, Oklahoma, where Carrie Groseclose lived (if I found the right Carrie for you in my previous post). I haven’t yet found the relationship to Ben Shipp, if any. Posting this info is just a long shot. If relatives of Ben Shipp can be found it may be possible to locate someone who knows the story of your father’s parentage, or has other clues for you.
James Swepton Shipp (his name per World War II Draft Registration) Lived in Hydro, Caddo Township, Caddo County, Oklahoma Wife Emma Born 26 June 1888 in Straight Horn, Mississippi
CHILDREN of James and Emma as of 1930 census in Caddo, Caddo, OK: May born about 1913 Albert born about 1914 Maurine born about 1916 Mearl born about 1918 Ollie born about 1920 Ruth born about 1927 Opal born about 1928 Betty Jo born about 1930 All children born in Oklahoma.