I have some info on Marie Bonk (1894-1976). Her Father was Joseph (1867-1910) and was my wife's Grandmother's Brother. Their parents were Thomas Bak/Bonk (1815-1904) and Julia Sromolska (1836-1921). Julia was the 2nd wife of Thomas. I have the location in Poland where Thomas and Julia were married and where Joseph was probably born which might be a clue to where your Grandfather may have also come from.
I also have additional info if you are interested. Please advise.