Here is another angle for you to consider. My husbands family "deOng" escaped from France during the persecution of the Huganauts (a political/religious group) sometime prior to the mid 1800's. Wanting to Americanize the name they dropped the "de" which is a preposition meaning "of the" and just went by Ong. My husbands grandfather E.R. Ong had the "de" reinstated after WWII because he had moved to Calif. and there was confusion due to the large Asian population. There is a mustard growing region in France that carries the Ong name. We are unsure if there are others who may not have changed the name back but I am guessing it's possible.