Thanks so much for searching for me - it is much appreciated.
It's a shame that there does not appear to be a common set of parents (or even a father) for any Charles, Richard & John

Unfortunately my Charles Brooks was born circa 1776 so cannot be the one listed for 1796.
North Leigh does seem to be a good place to be looking though as it is very close to Witney. The search continues...
Thanks again
Julie