Today I found the rest of my family.
I got a letter from my Aunt Helen, my father's youngest sister. She lives in Tarnow, in southern Poland. She doesn't speak English. I don't speak Polish. I sent a snail-mail letter in English and Polish. She responded via email (wow, they have computers in what I called "the old country" growing up) in Polish. Her niece's daughter says -- in English -- they do want to meet me. I translated the letter using one of those online translators. It says something about small potatoes, apparently. Feels like big ziemniaki to me.