Madliborg=Modliborz, Poland?

The Ellis Island site gives the place of origin of a friend's
grandparents as MADLIBORG, RUSSIA. They were actually Poles,
apparently in the Russian section of 1912 Poland. However, Madliborg
sounds more German than Russian, plus a web search on Madliborg
turns up nothing. I realize that the Ellis Island site often makes
transcription errors, but I'm looking at the manifest and it definitely
seems to be Madliborg. In another section (address of relative or
friend) it seems to say Madliborg Warsaw. On entries for other
immigrants I see other Polish towns, also followed by Warsaw (example:
Sompolno Warsaw, Rosno Warsaw...maybe Roznow?). Looking at lists of
Polish towns, Modlib=F3rz seems to be closest, but I think it was in the
German area, not Russian. If German, I wonder if its German name was
Madliborg/Madliburg. Anyone have any ideas?

Hugh Watkins...

polish and other middle european place names have 3 or 4 versions
according to who was in charge
and which language was used by the administrators in the relevant years

old maps are a great help

AND
EG
Finnish people often appear in US records as of swedish or russian
nationality depending on the date

Hugh W