Thanks,
It is a possibility that this is the William Hart I'm looking for. My William Hart was born in Leicester in 1795 and served in the Royal Marines between June 1811 and June 1813. I don't know when he moved to Nottingham. He was a witness to the marriage of his brother John to Mary Timson at St. Margaret's church, Leicester in 1817. However, I do know that by 1829 he had moved back to Leicester. His occupation is recorded as a Framework knitter in the parish records for St. Margaret's.
regards