Hello,

I have both Marcus and Weiselberg names in my family tree. Here's the info:

Caroline Marcus married Jacob Farber, (I do not have birth/death dates or locations) and had the children:
Caroline Farber
Josef Farber
Rose Farber
Marcus (Max)Farber
Anna Farber
Simon Farber
Amelie Farber
Sigmund Farber

Marcus Farber, b. 1860 in Lanzany, Lezany or Laczany, married Mary Schanzer, b. about 1863 in Lysowa. They immigrated to Buffalo, New York in about 1907.

Marcus and Mary had the children:
Solomon Farber
Oscar Farber
Josef Farber
Natalia "Nettie" Farber
Eva Farber
Charles Farber

Natalia "Nettie" Farber married Harold Weiselberg, and they had the children Solomon Weiselberg and Harold Weiselberg.

If this sounds like your family, I'll be happy to trade info.