The relative in Florida is a professor of computer science at NYU, and I'm looking forward to meeting him, giving him an advance copy of the book, and finding out what family history he knows. (Unfortunately, my grandfather didn't write nearly as much about this brother, who was a Torah scholar, so he won't find a lot in the book about his father, but at least there's something).
But neither he, nor the cousin in Florida, is from either of the other two siblings about whom I have not been able to learn anything. I checked the Mormon database, Shenandoah, PA death records, and what little still exists of Jewish records from Poland. I suspect that the sister, Malkah, and the oldest brother, Mordechai, who saved my grandfather's hide so many times, never made it out of Poland. I just don't understand why my mother knows virtually nothing about this aunt and these uncles (she says it wasn't something that was talked about). None of this makes sense to me, but I'm excited to have the chance to connect with these other branches of the family. It's another way of bringing my grandfather's story to life.