The cap bands, the nib and the clip are what count. The Meisterstück with two cap bands came onto the market in 1929 and was supplied at first with a different nib and without a clip; the nib of the familiar version only appeared from 1930. Three kinds of clip have to be distinguished: the slip-on clip, the ball clip and the teardrop clip. The ball clip was usual until about 1931 and the teardrop clip followed it, both forms being available at extra cost. A clip from the second price class fitted to a Meisterstück is not original. The standard reference for Montblanc writing instruments before 1950 is the Montblanc Diary by J. Rösler together with the second volume by Rösler and Wallrafen; information from boutiques and figures given in lists on the internet, by contrast, have repeatedly proved unreliable.
As to value: a black hard-rubber safety pen counts as a comparatively ordinary piece, being neither colourful nor made of precious metal. Signs of use, worn engravings or a bent nib bring the price down. A premium for patina, of the kind usual with vintage cars, is unknown in the pen market.