Looking for Szterns from Dobrzykow Nr Plock Poland

My great grandfather was Shammah Jerucham Sztern born abt 1850. He was married to Chaya Rochel Shein who was his first cousin. They and all their children mover to London in the early part of the 20th century.
Shammahs father was Israel Sztern who was married to Hanna Yenta Shein the sister of Hirsch Joseph Shein, father of Chaya Rochel.