In the photographs, less than brilliant, you may notice some of the distinguishing features between the 202/4/6 series and the 212/4/6 series. Obviously, the clip design is different, but also the grip section shows some differences; the 202/4/6 series has an edge separating the section from the body whereas the 212/4/6 series has a smooth transition from section to body. If you look carefully, you can also see that the end of the section is rounded in the 202/4/6 series but beveled or cut off in the later 212/4/6 series. Looking at the cap-photos below, you will also notice the difference in size; the caps of the later model being somewhat longer (the caps shown next to each other belong to the same pen size (2 and 4 in the examples).

It also seems that the gold plating improved in the 212/4/6 series.

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