I'm not sure I can offer any help, but I do have some questions on what you've done so far in your search. My search for my birth father resulted in finding 3 sisters! But I had more to go on than just the surname and even that took me years to get through. If you'd like I'd be happy to share some of the things I did to facilitate my search.
I also have Youarts in my family tree, although haven't done too much in researching them to this point.
Sue Stockwell
email me direct:
wolfspirit@gtlakes.com