There is a lady in Australia that is researching your Cornelius, b. 1819 WB. I believe he was a brother of Wm and Charles Dancer. Wm was born 1812 at Wednesbury, died Jan 17, 1888 at WB. Charles was born 1817 WB. The 1881 census shows Wm and Charles living with their wives at WB. Know Wm was a miner. Wm married 1834 to Sarah Fieldhouse whose daughter Ellen married David Bowdler, my gggrandfather. The lady of Australia said that Cornelius married Annie Cook and had a son named Wm Charles.
Haven't really researched this line back yet. Hope this info is helpful. Don of Dallas