has MARCELLA SCHNECK B. 02 Apr 1920 D. Jan 1987 in ZIP 06351 (Jewett City, New London, CT)
If that is her, you can get her SSN application for $27, which may have her parents' names and brth place. They may be accurate even if your GM made up the exact date of her birth.
Poland is a flat country between two agressive ones; a lot of their records wee burned, lost, used for warmth, etc. Genealogy would be chancy even if you spoke Polish and livedd in Warsaw. You may have a brick wall there forever.