Well, I'm a living Oestreicher and I can tell you a little about the name - my family were Bohemian Jews living in and around the towns of Tachau, Straz, Arnoltov, Kurschin, Pizan, Neudorf, Bruck, Nackentendorflas, and further along East, into Prague. They came to the United States starting around the 1850's, and were German speaking. They managed to stay in the countryside on the ever changing border of Germany, despite Jews being expelled, but as things got worse and worse, they emigrated. They were merchants and shop keepers and opened several frame shops which later became art galleries in New York City.