Kosko, Nowacka - Looking for relatives originally from Ostrow Mazowieski

I would like to visit Poland, but only if I can find some relatives. Both sides of my family came from Ostrow Mazowieski. My father's name was Kazimierz Kosko (1907) and his parents were Joseph Kosko and Walentyna Nowacka. He had two sisters who remained in Poland. I think that one married a Lewandowski and they had a daughter Asia. My mother's name was Balbina Brejnak (1909). Her parents were Kazimierz Brejnak and Anna Przybylowska. My mother had a brother Henry who also stayed in Poland and I believe had a couple of sons. I would love to find any of my nieces or nephews.

Was your father's sister's name Zofia (Kosko) Kempisty?

KOSKO: Origin uncertain; possibly a shortcut form of Kostko (pet form of Konstanty) of toponymic tag from Koski; a kośka was a priest's fur cap back in the Middle Ages (Rey writes about them).

PRZYBY£OWSKI: Topo nick from Przybyłów or Przybyłowo (Newmanville, Arrivalton).

BREJNAK: possibly from brejna, breja, bryja, (thick gruel eaten by poor peasants)

LEWANDOWSKI: Topo nick from Lewandów or Lewandowszczyzna (Lavenderville).

KEMPISTY: probably topographic from kępa (grove or clump of trees) or toponymic from one of many localities in Poland called Kępa.