OK update - one of Sir Luke Fildes's sisters, Isabella, has a descendant who has researched the tree and has confirmed (on a posting on the internet) that
1) Mary and William did have a son called Thomas
2) That they named some, if not all, after political figures/radical thinkers.
3) William and Mary had a son called George - G Fildes, son, was the person who registered the death of Mary Fildes on the certificate I have.
Its looking really good this.
I'm so impressed with the people who have helped on this.
Now to try to contact this ancestor who has the info on William and Mary,etc.
Thanks again, everyone,
I will let you know how I go on......
Claudia