I've just got my first safety razor, which is a vintage, brass nickeled Gillette Tech. I cleaned it and gave it a try- the tool gave me a very pleasant and gentle shave. I fitted it with a new Wilkinson Sword blade and to my surprise it does not quite seem to fit very well. Although it shaves well, the blunt and narrow sides of the blade stand out of the razor's head by about 2mm on each side. Is there any idea behind it or have the blades dimensions been changed since my razor was introduced to the market? (Am I right to think it's about 1940)? I marked the spot with a red square on the attached photo.