Hi Kath,
Yes, I think I can detect William Sims on my tree! Basically, I believe all the Howden Simms/Sims descend from James Simms and Elizabeth Brown (who were born in the early 1700s).
I think your William is the son of James Simms and Ann Holdsworth?
So:
James Simms and Elizabeth Brown (Gen 1)
James Simms and Susannah Elcock (Gen 2)
James Simms and Ann Holdsworth (Gen 3)
William Simms and Martha
Does that tie in with you? My family is another branch from generation 2, James and Elizabeth's son David, as opposed to James Jr.
Claire x