Have you checked "A Dictionary of Jewish Surnames >from the Kingdom of Poland" or "A Dictionary of Jewish Surnames >from the Russian Empire"? Both are by Alexander Beider. The Call Number if these books are at your local library is 929.42. I have found these dictionaries to be very helpful lately.
Those books a great source of information, indeed. Town Jaworow, where Dann family is from, has nothing in common with the Kingdom of Poland or Russian Empire. Galicia was a bit different planet in a Jewish world.
