Short of a manual the book Wireless for the Warrier is the bible on British and Commonwealth manufactured Radio's.
These particular generators came in late war when these sets were being used in a more mobile role. Larger British manufactured sets were used previously. Judging by the number of these Generators which seem to have survived, presumably they did not see large scale use.
http://wftw.nl/wftw/volume1.html
http://wftw.nl/wireless/wireless.html