Hi Anna,
My grandfather Stanley changed the spelling of our last name after he got back from fighting in the Pacific during WWII from Gnys to Ginish (fairly obviously so people would stop butchering the pronounciation of it). Most of our branch of the family is based out of Rhode Island in the states, and I believe my great grandfather Walenty Gnys was the first family memeber from our side of the family to come over from Krakow. He had married a woman named Josefine (spelling is prob wrong there) and when she passed he went back to Poland to bring back my great grandmother Kunegunda (great Polish name). I believe we changed our last name around 1945,but other than that we haven't been able to trace our roots past Walenty and Kunegunda 3 generations back (turn of the 20th century).