I think there are two ways you can go, at least with the place names: you can use the conventional Polish spelling or you can transliterate the Yiddish into something that represents the pronunciation to an English speaker. The first is accurate, checkable and reproducible, but doesn't really help most people reading the stories; the second is vague and subjective but potentially more comprehensible to the average reader. Lack of consistency is a problem and both rely on knowing what the original name is. Sometimes the inconsistency is in the source - I've encountered this problem with Japanese names in Polish documents I've been translating into English. Have they been declined as if they were Polish? Sometimes they have, sometimes not, and sometimes they've been transliterated into an English spelling - which then might have been subjected to Polish declinations! If you're not familiar with the original it can be easy to accidentally mangle a name.