Quesion Jewish Last name?

What you are trying to do is determine what is the dividing line between Germans and JEWS which are almost indistinguishable, unless you are talking about the hardcore Jewish traditionalists who look and act the part and usually do not marry outside of their group. When WW2 ended you had men {soldiers} from all nationalities descending upon Germany and they married a lot of German women because all the German men were dead or mangled. I am the offspring of one of those unions and I have brown skin. So what Adolph Hitler intended had the total opposite effect in the end. Germany now is a mixed bag of people and languages; although the official language is German. Basically terms change over a period of time and it would be almost impossible to do what you are trying to do. Check out Arnold Schwarzneggers' last name, who do you think his ancestors were?