I don't work in colonial history, but if you do, the Families in British India Society may be of some use. Check out their page of research advice at https://www.fibis.org/help-and-support/research-help-and-advice/. Most importantly for those of limited funds and mobility, the FIBIS can offer assistance in searching records at the British Library and other London archives. The current membership fee is £15.00 / year.
