The coloured Montblanc fountain pens of older construction count as outright rarities; to see four such pieces side by side was an exceptional case at the Cologne collectors' meeting in 2004. Also singled out there was a new Montblanc 149 in the demonstrator version, which is considered extremely rare. In 2005 a particularly well-preserved Montblanc 139 and a striped 144 were among the highlights on offer.
A special form in its own right is the Montblanc Carrera with piston mechanism. Only a few examples of this model were built with a piston filling system, which is why such a piece counts among collectors as a remarkable find. More widely sought after, but far less rare, are Montblanc writing instruments from the 1960s and 1970s; in 2005 they formed a focus of the offering in their own right and were in demand above all in the afternoon.