I also have heard stories and like yourself would love to find the documentation. I am also a member of the Bradt Family. My lineage goes back to Albert Bradt who married in l632 Annatje Barentse Van Rottmers. My line then follows Barent Bradt m. Susanna Meyer , Anthony Bradt -m. Willempie Tanise, Anthony Bradt and Rebecca VanderHeyden, to Daniel Bradt m. Alida Quackenbush and their daughter, Judah (baptised Judikie at the Schaghticoke New York Dutch Churuch-married William G. Waldron in l804.
I am also a member of the Bradt Family Society which has a large reunion every 5 years. They meet this year July in Albany New York, with members nationwide.