I have sorted this problem out. John Rickward did indeed marry Eliza Fosbrook they emigrated to the USA (New York, Ulster County) in the 1850's -can provide date- he is recorded as Rickwood. Given the dialect from the area he came from and the fact he was illiterate he would not know if the spelling was correct. He was the brother of my Gr Grandmother. These facts are true.
I should add one of his sisters followed him in the 1870's and lived in the same area.