Dear Tanya,sorry to see you are still searching for your Bates
There is a death for a John Bates registered in June qtr 1839 in the Leighton Buzzard district, try freebmd which has traditionally been the registration area for Marsworth, Cheddington and surrounding villages.Because Marsworth is on the boundary of three counties, Bucks, Herts and Bedfordshire, your Bates could have lived anywhere around the area. eg. Ivinghoe, Drayton Parslow Tring,,Bucks Record office may well have the Parish of Marsworth church register entry for Johns marriage and any other info you may seek,perhaps some kind soul would look for you, or you could enquire and purchase a copy which might give you other infomation or clues. I no longer live in this area, although all my ancestors come from Marsworth I hope this helps
Marton