1. The Miller surname
My paternal grandmother’s maiden name was Miller. They immigrated to New York from Brest-Litovsk around 1905-1910. I’ve found some records of the family in NYC, but few Ellis Island records, and nothing at all from Brest-Litovsk. A possibility is that they changed their surname at some point. I have no idea how to determine the old surname. Miller is a valid Yiddish name, though my grandmother asserts that her grandparents spoke Russian rather than Yiddish. Before you ask, I already tried spelling variations of Miller.
A link worth checking: http://www.ics.uci.edu/~dan/genealogy/Miller/othrmilr.htm#Reuben
2. The Joondeph family
My paternal grandmother had an uncle who married a Rebecca Joondeph. The Joondeph family has the same story as the Miller family – they exist in NYC records, but nothing before that. I thought it was likely that the families knew each other before moving to New York, and thought that learning about one family might help shed light on the other. I contacted some living Joondephs, but unfortunately none replied.
My grandfather speculated that Joondeph could be an unusual Anglicization of the name Yontef. I haven’t pursued this yet.
3. Rachel Mautner birthplace
We knew the Mautner family as being from Austria and somehow got it into our heads that Rachel (Ruchel) Mautner was born in Vienna. There were lots of Mautners in Vienna, so this seemed reasonable. In the few records we found, she gave her nationality as Austrian. However, we thought that her family from further back was from Belz, and she lived in Belz before she moved to London. So how was she born in Vienna? The answer is that Vienna was a spurious attribution, and you have to pay close attention to changing borders. Belz is in present-day Ukraine, and it was part of Poland and Ukraine since WWI, but before the collapse of Austria-Hungary, Belz was part of the Austrian empire, and its occupants were Austrian citizens. It seems that the Mautners and Zwerlings identified as Polish.
This is a common issue in Western Europe where borders changed a lot in the 19th and 20th centuries. I also struggled a bit with the Alzufrom family, who also thought of themselves as Polish, but are also from a town that is in present-day Ukraine.