Hit the antique shop in town on a whim even though most times they've either got bupkis or have been just cleaned out. Today they actually had something,an extremely grungy Schick Krona for a five spot during their 50% off sale so I figured it was worth 2.50 to try a Krona but I've now got a few questions. 1 It's currently going through a thorough cleaning and the metal TTO knob has gunk in the ribs on the knob,while a lot of the gunk has come out there is still some gunk really holding on and almost looks like it could be remnants of black paint. Did the metal knob Krona's have paint in the ribs or is that just really stubborn grunge? 2 I know that the letters and numbers stamped on the underside of the head are some sort of Schick mystery code and have no connection to dating the razor. From my searching most of the Schick sites are a wealth of info on narrowing down the date or at least era of your Schick injector but squat on spotting features of the Krona eras. Does anyone have a few spotting features to narrow the date on my Krona? Photos to follow but mine is the standard plastic handle,metal head and ribbed metal TTO knob possibly with black paint in said ribs.