MORDKA RUDOVICH or RUDOVIZCH - help me find my grandpas family members

hello my name is andrey or in polish andzej, Im looking for my grandfathers familly.
the thing is that they were sepperated in 1939 and i found out the story of my origins only a few years ago.
the only thing that i know that his polish name was MORDKA RUDOVICH or RUDOVIZCH.
if any one have herd about people with such family name please let me know. i have been looking for a years with out any foundings.

Thank you for your cooperation.

MORDKA: diminutive of morda (vulgar term for mouth such as yap, trap, snout, etc.). However, since you are from Israel, Mordka could have dervied from the Jewish name Mordechaj.

RUDOWICZ: patronymic, ie son of Rudy (red-haired bloke).

No other info? Maybe a city/town/village, or even county name? Any other family member names? Dates, like birth, etc.?

The name just does not sound Polish to me.. It looks like a Serbian, or Ukraine.

The largest single Mordka concentration is found in the greater Radom area south of Warsaw. A smaller pocket may be encountered in SE Poland's Tarnobrzeg area.

The main Rudowicz stronghold is western Poland's Wielkopolska region, specifically the city of Kalisz and environs.