Alberto Guido Chester
If you look at telexplorer.com (white phone pages fo Argentina) you will find only 10 entries for the surname WILLIG (which seems to be your relatives surname)
Some of the names are duplicated (vacation homes probably).
I suggest you write by snail mail to these people, explianing the relation
Writing is Spanish is highly recommended.
Some picture to show you are not a scam is suggested.
And suggest a follow up via mail.
People here are quite disenterested in ancestry... or is it everywhere ?
Guido Chester from Buenos Aires