I have found an advertisement which was carried in the Northumberland Advertiser of 13th March 1832, headed 'North Shields Pottery' and going on to inform the public that the North Shields Earthenware Manufactory is now carried on under the name of "Cornfoot, Carr and Co." and continuing "C.C. & Co. take this opportunity of announcing....."
So the C. C. & Co mark appears to have been used beyond 1832 and perhaps into the 1840s. This has implications for the circular plaques with the impressed C. C. & Co mark. Perhaps some of them were produced later than is generally supposed.