I see you have friends in Oldenburg. My grt-grt grandfather, Joseph Derner, supposedly came from there but can't find any information on him. He was Catholic and born in1814. In 1853 he came to NYC on the same ship as his future wife, Theresia Merkt, who was from Speichingen, Germany. He was a master carpenter.
If you discover any Derners in Oldenburg please let me know.
Thanks
Kay Brown. brownkderner@aol.com