There are brief references in Jewitt's Ceramic Art of Great Britain and in Encyclopedia of British Pottery and Porcelain Marks by Geoffrey Godden. Might be available through your local library, and the latter could be held in the reference section. Nearest libraries may have local history collections with background on this pottery.
Having said all this I see that this pottery has appeared on Rootschat before in some detail, and I note that by googling "Coleorton Pottery" numerous potential contacts and sources present themselves. The pottery seemed to be the subject of voluntary liquidation in 1936.