It's been a long time since I posted this original post however I now believe my James Banks is most likely to be the James christened in Hail-Weston in 1760 (son of Richard and Sarah). The most likely parents are Richard Banks and Sarah Swepton who married there in 1760.
I can't find any record of his brother Edward, but it looks like John was christened in 1756 and Mary in 1765. This would seem to suggest that Richard was married twice, and that James and Mary were born to a second wife.
The other children I've found for Richard and Sarah are as follows:
Jeremiah - christened 1741
James - christened 1745 [presumably died young]
Richard - christened 1747
Sarah - christened 1749
Ann - christened 1750
William - christened 1753
John - christened 1756
Elizabeth - christened 1763
I think all of these children, bar James (1760) and Elizabeth (1763) must have been to a first wife [called Sarah I suspect] and the last two were the children of Richard Banks and Sarah Swepton.
I think Richard might have been born in Hail-Weston in 1713, the son of William and Ann Banks.
I can't find anything about the uncle "Thomas" or aunt "Jane" so I will have to go back to my notes and check on them.
Matt