I have just discovered this message board and would like to add my 2 cents worth.
My great great great grandfather was George Doubell born 1787. He married Elizabeth Crunden. I do not have any more info on these people and family legend is that George came from Scotland.
George and Elizabeth had at least one child Catherine Doubell, my great great grandmother, born 1813. She married John Grant Sargent. At the time of their marriage they were living in Reigate, Surrey, England. They had eight children from whom my grandmother is descended. John Grant Sargent was a Quaker and they eventually settled in Fritchley, Darbyshire where they founded a very strict Quaker sect. John Grant did a lot of trading with France. I understand that there was also a Jane Doubell (I think she was Catherine's sister) who was a businesswoman, I think she was a grocer or a tea merchant.
If the above information applies to any of you who have posted messages I would be very interested in hearing from you as I have not had much luck in finding out about the Doubell's.