For those collectors trying to match their identifiable commercial silverware to the correct china service that it accompanied, this may help you where John Maddock & Sons is concerned. The impressed crown and numeral date coding system appears to have started during the reign of Victoria (still trying to break this code) and runs through Edward VII & George V. At some point, an ink stamped letter-number code begins. So far, I believe the letters are sequentially ordered to represent years and may have started with "A" around the time of George's demise in January 1936. Why? All later letter codes (V, W, etc.) appear in the era of "Ultra Vitrified" wares with backstamps dating from 1955+. Additionally, sometime prior to 1972 the code system changes to a straight number-number stamp (i.e. Month/Year such as 5/72). Logically, if "Z" occurs during the 1960's, then "A" must have begun after c.1936. If I can ultimately find the actual switch-over dates, I will post them for you. (It is not known if the number after a letter, such as "W-4", represents a month or a quarter.) All of this is preliminary work only and not conclusive. Hope this helps you match your services to your silver. Maddock wares were used around the globe.