Hi Julian. Brown-Westhead, Moore & Co. were in business 1862-1904 in Hanley, Staffordshire. The impressed diamond mark is for January 23, 1875, when BWM & Co registered dinnerware shapes. The company used the same shapes for a number of different printed patterns, including this one which is registered in 1886 (the 42332 number) and probably produced for several years. Have not been able to find a pattern name yet - some of the patterns apparently didn't have names - but hopefully some more information will turn up.