1970s Pelikan 400NN in black by Merz & Krell.  After Pelikan began its decline and stopped producing the 400NN, they discovered a niche market for the 400NN, according to some in Asia. Normally these pens are pretty uncommon, but someone discovered a trove of them and I was able to get a handful. The pens look very much like the earlier 400NN, but vary subtlely. Most obvious is the smooth turning knob/barrel interface. Normally, the pens go for a premium, but I am able to offer them at the same price as for the standard 400NN. They come in box, new old stock with sticker and papers and with fine and medium nibs. $295.00.