In www.jewishgen.org/jgff/jgffweb.htm you can find addresses of researchers for JACOBS from Poland. The closest to what you are looking for is:

Gertrude Singer Ogushwitz (#1139)
gsogush@snet.net
Researching Jacobs from Wloclawek, just 12 miles from Dobrzyn (Dobrzyn nad Wisla).

If you contact her or others you may find a lot of information.