I was born 1945 and raised in White Castle.My mother still lives there.I don't remember anyone with the DEVILLILER surname from that area.Maybe the family left before my time.
About 1951-52 I remember the Catholic Church burning to the ground.It was arson and us kids watched it go as the mad man that lit it jumped and screamed on top the adjacent Mississippi River levee. I think all records were lost in that blase but I was just a kid so maybe something was salvaged.You might try calling the present day rectory of Our Lady of Prompt Succor Catholic Church in White Castle to find out.
The local area, Bayou Pigeon, Bayou Goula and more wereall served by priests from WC, so those records may be smoke also.
The Barbay's were an established upscale family of WC back then.There are still Barbay's there.
You should be able to find parents and siblings in the census of LA of 1860,70,80,1900,10,20,30.