Based on research of Tara Salman:
Szymon Pfefer and his younger brother Majer Pfefer (also known as Symcha Manela or Mendel Pfefer) settled in Ostrowiec in the second half of the 1800’s. Their families, who were kohanim, were prominent among the other unrelated Pfefer families that lived in Ostrowiec.
The Pfefer family greatly contributed to the economic and social development of Ostrowiec, especially in the trades of construction and finance. One Pfefer ancestor opened Ostrowiec’s first bookstore. Two Pfefer brothers owned lotteries and their father was a banker. The most famous of the Pfefers was probably the industrialist Mojzesz Pfefer (1855-1919), who financed construction of a synagogue in Kielce in 1903.
Although Ostrowiec was this Pfefer family’s base, they lived all over the Radom-Kielce area and originated in Nowe Miasto nad Pilica in the Piotrkow province.
Mojzesz Pfefer
Pfefer lottery ticket
More detailed information about this family can be found on Tara Salman's blog