Thanks. You are so gracious to reply. As far as I can tell Agustin's wife was Madeleine Lane or possibly Madeleine Sin. Lane is not a very French or Sardinian sounding name. My guess? it was a mistake and might have come from the last syllable of her given nmae, Leine or Lane. Her name, Sin was found in one record.
As far as Marongiu , you have pronounced the name as I suspected. Our name in Louisiana Bayou French is pronounces Ma (as in mama) ron'(on with an r) and with a soft g or je. Ma ron' je. All of my searches turned up only one Maronge, a Marcel or Marcello who is a fashion designer in Paris but I think he is Italian.
I do not know what village or even what district Agustin came from or Marcello for that matter. I'm also not sure Agustin ever came to Louisiana. I do know, according to RC church records that Agustin was born around 1730 in Sardinia and Juan/Jean arouns 1765 in Sardinia as well. At that time the island was, as a result of the Savoy treaty a part of the Piedmont and Sicilian kingdom and I believe was know as the Kingdom of Sardinia. The first Maronge, or Moranges, or Maranges (there was a lot of creative spelling occurring in those days and it makes it difficult to know what was correct and depended on the nationality of the recorder in LA) as far as I can verify was Jean or Juan Constantin. There are records using the Spanish Juan. I can't tell if that was a translation or his given name.
I appreciate your offer to help and will see what I can find that will focus the birth place of either JuanJean or Agustin.
Regarding the Sardinian penchant for pronouncing Shepley as Chaplin, you don't tend to wear black bowlers, baggy black trousers and walk with abbreviated steps while twirling a cane, do you? Just kidding. AND I also noticed a Zola in your name. Is that you husband's surname? Is he related to Emile the French author, whose father was Italian?
I'll do a little more digging in the Ancestral Garden.