Thank you for answering so quickly...
Definetly, we're not talking about the same Isaac. My grandfather came to Argentina around 1900, and he had 7 children.
I haven't heard of any Zamuchovsky, because I live in a little town. But in Bs. As, there is a very big jewish community, so it's most probable to find them there...
Thanx again,
Liliana Yankilevich.