Looking for Ancestors of Thomas Shead B 1816 Born Weathersfield OR Wivenhoe Essex England

Thomas Shead married Elizabeth Mitchelson Barltop b abt 1822, in 1842, daughter of Benjamin Barltrop and Mary Mitchelson. Some of the children emigated to Australia and some to the United States.
I am very interested in going back further in this family tree and do think I have come across Thomas' parents, and a sibling, but I cannot be sure. Any help would be very much appreciated.