I am searching for my relatives also. My grandfather was Eugene Joseph Francois born in Glynn, LA near New Roads on August 19, 1878 (as found Ancestry.com).
( From your post ----- 3. Gustin Grancoise (Augustine Francis) was b. 1842. He married Idelle. She was b. 1843.) These two may be my great grandparents.
His parents were Augustine (Gustine) Francoise (Francois/Francis) and Adelaide (Delie).
Eugene's siblings were: Hentietta, Valerian, Louisa, Lewis, Willie, Olivia, and Oscar. There may have been others.
My grandmother was Cecilia Viola Farbe/Fobb. Her parents were Louis Fobb and Henrietta Noel of New Roads, LA.
My father was Frank Francois (Simmesport, LA). His siblings were Willie Francois, Elouise Francois-Smith, and Henrietta Francois-Jackson (Lettsworth, LA).
Please reply if you think we are searching the same family.