I stumbled across a portal that gives access to digitised papers and notebooks from Charles Booth's survey, including some that don't seem to be available through https://booth.lse.ac.uk/

The main page for the Booth Survey is here (note that most of these web pages are in Portuguese):
https://lse-atom.arkivum.net/uklse-dl1cb01

The full list of contents of the digital archive is here. It includes some statistical publications that perhaps could be useful:
https://lse-atom.arkivum.net/