Here are some additional resources and links relating to Baptist History both in Northamptonshire and elsewhere in the UK.
Byepaths in Baptist History by J. J. Goadby, published in 1871.
Summary of Baptists Ministers in Northamptonshire, Bedfordshire and Huntingdonshire 1753-1835
Directory of Baptist Ministers in England and Wales from the Baptist Magazine 1811
Ministers in Northampton in the 1841 Census (Baptists and others). This information is supplied by Alan Clark, who has an indexing project of the 1841 and 1871 census in Northampton.
The State of the Baptist Churches in Northamptonshire in 1814 by Andrew Fuller.
Baptist Churches in Cambridgeshire a list compiled by Janet Hurst
BAPTIST HISTORICAL SOCIETIES
There are two UK based Baptist historical societies:
Baptist Historical Society
The Strict Baptist Historical Society