While I do not have a record of your father Elbridge Erwin Ostic, I do have the following information:
Tressie Ostic, b.about 1894 Charles Ostic, b.1900 Moses Ostic, b.1909 Vern Melvin Ostic, b.28 Dec 1896 in MI, m. Gladys Alvina Parker, d.May 1982, only child I have listed is Vernon Jay Ostic b.1925.
Tressie, Charles, Moses, and Vernon were the children of William George and Effie Ostic.
William was the brother of my grandfather, Omar Ostic, and son of John Ostick and Anna Whitehead.
We are 2nd cousins, once removed---I am a generation older than you.
I too have often thought the origin of the Ostic name sounded Slavik, but so far I find them in England back to about 1725 through several name spellings, the earliest of which is Austick.I did find a Christian Ostick in Vilnius, Lithuania around 1425, but since there are 300 years unaccounted for, we can't really claim him as our own!:~)
Please feel free to e-mail me at firstname.lastname@example.org with more info.I'd love to know more about your family---names, dates, and places.