Levin is a well-known Jewish surname; here in South
Africa its owners pronounce it LuhVEEN, which is close to the
German version
Satu gave us. But in England I've heard it pronounced LEVVin, e.g.
Bernard Levin, journalist and TV person.
So, maybe the Levein spelling was an attempt to keep the German-Jewish pronunciation instead of the British-Jewish one. (My guess is that anyone named
Moses in the 19th century was likely to be Jewish. Not today, though!)