Hallo Richard Shindle,
I joined Ancestry.com just a week ago and by searching the last names Anweiler and Anwiller i ran across your message from 2001.You may already have all your questions answered but anyhow let me try to tell you what I know about this surname-variations above.
I am living in Mannheim,Germany.Born in 1937 in Hungary where my Forfather Mathias Anweiler?Anwiller? immigrated to around the year 1755.He came from Germany but up to now I could not trace the village he was born in.I am quite sure that it must have been the Palatine area close to the French border.In this area nowadays called "Rheinland-Pfalz" there is a town with the name Annweiler and is very likely that the surname Anweiler is derived from the name of this town.
The funny thing about my forfather Mathias is that in the churchbook of Csatalja where he married Anna-Maria Hiegler his last name was put down as Anwiller,according to the slang pnonounciation in the Palatne dialect.When his third child was born the priest all of a sudden wrote down the surname Einwiller and this name was than used continuosly for all his descendants.
So you see for the immigrants to the States Anweiler changed to Onwiller and for the immigrant to Hungary out of Anweiler it became Einwiller.Most likely this happened because in these days people could not read nor could they write and the immigration officers and priests wrote down what they phonetically understood.
Because I am still not done with my search on Anweiler/Einwiller I would very much appecciate if you would get in touch with me to exchange what ever we know about these ancesters.
Hope to hear from you

Andy Einwiller