He may well have been a Baptist in which case tracking his family down prior to 1841 census is going to be a hard slog.
As a pointer .. if my theory is correct they were existent in Frome Somerset as well as Westbury Wiltshire which towns were only about 5 miles apart.
The name 'Doel' exists at Dilton near Westbury Wilstshire and the name appears in the Baptist 'Providence' chapel there and suggest you try this link;
http://www.dilton-marsh.org.uk/research/default.phpand on the 'search' page type in DOEL where you will find researchers of that name.
A William Doel wrote 'Twenty Golden Candlesticks' (google it) which relates to a history of nonconformity in western Wiltshire and you may be able to obtain a copy.
Sorry for the length of all this ...... it stems from a long and difficult search for Dilton ancestors that I had no idea were Baptists and the fact that Baptists as a rule do not baptise their children until the children are ready to understand why they are being baptised and in my case the baptism of my 2nd gg/m Ann Adlam has never been found ... perhaps she was never baptised but from all available censuses she was born circa 1811.
Hope it helps.
joboy
