After researching in Dutch birth/marriage archives in Amsterdam I found out that my forefather Jaques du Bois came from Elbing / Elblag. He was married to Johanna Sophia Wilson.
He had at least one son named Charles Henri du Bois, born around 1780 in Elbing and moved to Amsterdam around 1800.
This summer I am planning a trip to Elblag, but If anymore has more information about this family, please let me know.
If it can help anyone, there was a lot of traffic between the harbours of Elblag, Amsterdam, Bordeaux and Cadiz (France)