Searching for family name of Rabbi David, ben (son of) Moshe of
Kletzk. David was the Rav of Novarodok during most of the 19th
century. His son, Moshe, who died young (age 30) adopted the name
HOROWITZ as per his father-in-law's name (of Minsk). David's father
was not R' Moshe EISENSTAT of Kletzk.

The possibility that he didn't have a family name is strange since his
father's contempory, Moshe of Kletzk had a name-EISENSTAT and the
Rabbis of Novarodok before and after him did have.

I would also appreciate knowing about other children of his father (Moshe).

TIA

Yoni Ben-Ari, Jerusalem