Well, I am not as far into my genealogical research as you are, but I do have a DOR/DUERR/DORR/DUR in my family tree. Louise DOR/DUERR/DORR/DUR was born in the early 1800's to Gottlieb DOR/DUERR/DORR/DUR (wife unknown). Louise was born in West Prussia. She came to the United States with her husband Julius Gering/Gehring Sr. in approximately 1845. She lived in Oshkosh, Wisconsin until her death. Does any of this ring a bell. It is not a very common name (at least from my perspective) so I am wondering if there is any relationship here? Please get back to me--I have hit a dead end in the research of this branch. There is an interesting family rumor attached to her--I would be glad to share it if you are interested.