Okay this is getting silly now. Just found ANOTHER razor in ANOTHER charity shop. Pat: 133963 - 1917. So it looks like I have got the date of manufacture covered. Strangely enough it has an entirely different number on the plate that the blade rests on but they're just too small to make out. I have no idea what these numbers represent, or wether knowing them would help me learn anymore about this particular model. All i know is that it's made in England (case made in USA). I'm going to stick this on Ebay at some point in the near future, just wondered whether I should clean it up first, and if so how?