Thanks for your reply Glenys. Let me have your address and i will dig out the will and send a copy. Do you have evidence that John was the natural son of William? My research show that he was charity's son but no father is mentioned. Here are some details of John that I have - Mentioned in one of Stiller's obituaries, brother of Charlotte Sarah Parker/Marden.
1871 census: John MH Parker living with William and Charity in Crowboro'. Aged 9, scholar, born Withyham.
1881 census: John Marden, living as Boarder in Rotherfield, Sussex (Carpenter's journeyman)
Charlotte Sarah Marden (John's sister or half-sister) is my wife sarah's great grandmother. I have no further details of the parents of William Marden (b 1783 John's grandfather). However, I do know that Charity Parker's parents were Stephen Parker and Harriet Adams.
I would be keen to have any information you have on William Marden and Charity and your Marden line. My address is 5 Linden Lea, London N2 0RF. regards. Ray