Hi again
Just had a quick look at the info I have, which I have found via ancestry.com or from others connected to the tree. Some of it I haven't investigated further to confirm the info as yet but it might be of use to you anyway.
William Darvell b c1746 m Fanny Ware c1746 19 Oct 1769
Children - Thomas b 1770, John b 1772, William b 1773, Elizabeth b 1775 (think died 1776), Elizabeth b 1778, Joseph b ?. Matthew b 5/5/1781 (you have him b 1772).
I was aware of Matthew's marriage to Charlotte Lovet but I think he was married three times as I also have Jemima Lyon and Sarah Jordon.
I also have William b 1808 married to Rebbecca Wright but I have 10 children. Sarah b 1830, George b 1831, Charlotte b 1834, James b 1836, William b 1839, Mary Ann B 1840, George b 1843, David b 1846, Jane b 1849 and Elizabeth b 1850. On Ancestry it has the William and Rebbecca living at Waterside, Chesham in 1881.
It's quite a large tree, don't mind emailing you gedcom file?
Anne